Enable Solidity IR Optimizations (#71)

This PR turns on the IR optimization flag when invoking the Solidity
compiler for the Safe token lock contracts. There are small gas savings
across the board (exception with small gas overhead when withdrawing 0
amounts, which we do not need to optimize for) and moderate code size
savings:

### Before

```
·----------------------------------|---------------------------|------------------|-----------------------------·
|       Solc version: 0.8.23       ·  Optimizer enabled: true  ·  Runs: 10000000  ·  Block limit: 30000000 gas  │
···································|···························|··················|······························
|  Methods                                                                                                      │
··················|················|·············|·············|··················|·············|················
|  Contract       ·  Method        ·  Min        ·  Max        ·  Avg             ·  # calls    ·  usd (avg)    │
··················|················|·············|·············|··················|·············|················
|  SafeTokenLock  ·  lock          ·      44146  ·      87946  ·           74071  ·         31  ·            -  │
··················|················|·············|·············|··················|·············|················
|  SafeTokenLock  ·  recoverERC20  ·          -  ·          -  ·           52052  ·          1  ·            -  │
··················|················|·············|·············|··················|·············|················
|  SafeTokenLock  ·  unlock        ·      52127  ·      52151  ·           52128  ·         78  ·            -  │
··················|················|·············|·············|··················|·············|················
|  SafeTokenLock  ·  withdraw      ·      24190  ·      82140  ·           68218  ·         25  ·            -  │
·-----------------|----------------|-------------|-------------|------------------|-------------|---------------·
```

```
SafeTokenLock 5089 bytes (limit is 24576)
```

### After

```
·----------------------------------|---------------------------|------------------|-----------------------------·
|       Solc version: 0.8.23       ·  Optimizer enabled: true  ·  Runs: 10000000  ·  Block limit: 30000000 gas  │
···································|···························|··················|······························
|  Methods                                                                                                      │
··················|················|·············|·············|··················|·············|················
|  Contract       ·  Method        ·  Min        ·  Max        ·  Avg             ·  # calls    ·  usd (avg)    │
··················|················|·············|·············|··················|·············|················
|  SafeTokenLock  ·  lock          ·      43639  ·      87439  ·           73564  ·         31  ·            -  │
··················|················|·············|·············|··················|·············|················
|  SafeTokenLock  ·  recoverERC20  ·          -  ·          -  ·           51886  ·          1  ·            -  │
··················|················|·············|·············|··················|·············|················
|  SafeTokenLock  ·  unlock        ·      51633  ·      51657  ·           51634  ·         78  ·            -  │
··················|················|·············|·············|··················|·············|················
|  SafeTokenLock  ·  withdraw      ·      24261  ·      81598  ·           67836  ·         25  ·            -  │
·-----------------|----------------|-------------|-------------|------------------|-------------|---------------·
```

```
SafeTokenLock 4536 bytes (limit is 24576)
```

Author: nlordell

hardhat.config.ts

@@ -38,6 +38,7 @@ const soliditySettings = SOLIDITY_SETTINGS
   ? JSON.parse(SOLIDITY_SETTINGS)
   : {
       evmVersion: 'paris',
+      viaIR: true,
       optimizer: {
         enabled: true,
         runs: 10_000_000,

package-lock.json

@@ -9,7 +9,7 @@
     "test": "hardhat test",
     "test:e2e": "HARDHAT_FORK=1 hardhat test",
     "test:all": "npm run test && npm run test:e2e",
-    "coverage": "hardhat coverage --network hardhat",
+    "coverage": "hardhat coverage",
     "coverage:check": "istanbul check-coverage ./coverage.json --statements 100 --branches 100 --functions 100 --lines 100",
     "deploy-all": "hardhat deploy-contracts --network",
     "deploy": "hardhat deploy --network",

package.json

@@ -963,22 +963,7 @@ describe('SafeTokenLock', function () {
   })
 
   describe('Token Rescue', function () {
-    it('Should not allow non-owner to recover', async () => {
-      const { safeTokenLock, alice } = await setupTests()
-      expect(safeTokenLock.connect(alice).rescueToken(ZeroAddress, ZeroAddress, 0))
-        .to.be.revertedWithCustomError(safeTokenLock, 'OwnableUnauthorizedAccount')
-        .withArgs(alice)
-    })
-
-    it('Should not allow Safe token recovery', async () => {
-      const { safeToken, safeTokenLock, owner } = await setupTests()
-      expect(safeTokenLock.connect(owner).rescueToken(safeToken, ZeroAddress, 0)).to.be.revertedWithCustomError(
-        safeTokenLock,
-        'CannotRecoverSafeToken',
-      )
-    })
-
-    it('Should allow ERC20 recovery other than Safe token', async () => {
+    it('Should allow rescuing tokens other other than Safe token', async () => {
       const { safeToken, safeTokenLock, owner, alice } = await setupTests()
       const erc20 = await (await ethers.getContractFactory('TestERC20')).deploy('TEST', 'TEST')
 
@@ -1012,6 +997,21 @@ describe('SafeTokenLock', function () {
       await expect(safeTokenLock.connect(owner).rescueToken(erc20ReturnFalseOnFailure, owner, 1)).to.be.reverted
       await expect(safeTokenLock.connect(owner).rescueToken(erc20ReturnNothingOnSuccess, owner, 1)).to.not.be.reverted
     })
+
+    it('Should not allow rescuing Safe token', async () => {
+      const { safeToken, safeTokenLock, owner } = await setupTests()
+      expect(safeTokenLock.connect(owner).rescueToken(safeToken, ZeroAddress, 0)).to.be.revertedWithCustomError(
+        safeTokenLock,
+        'CannotRecoverSafeToken',
+      )
+    })
+
+    it('Should not allow rescuing as non-owner', async () => {
+      const { safeTokenLock, alice } = await setupTests()
+      expect(safeTokenLock.connect(alice).rescueToken(ZeroAddress, ZeroAddress, 0))
+        .to.be.revertedWithCustomError(safeTokenLock, 'OwnableUnauthorizedAccount')
+        .withArgs(alice)
+    })
   })
 
   describe('Operations', function () {