ci: use nix to run mypy type checks

The setup of the notmuch and gpg dependencies is quite complex and takes
a long time so it is easier to have nix prepare the environment in which
to run the type checks.

Author: lucc

.github/workflows/check.yml

@@ -34,20 +34,13 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
-
-      - name: Set up Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: "3.12"
+      - name: Install Nix
+        uses: cachix/install-nix-action@v22
 
-      - name: Install dependencies
-        run: |
-          pip install mypy
-          pip install -e .[typing]
+      - uses: actions/checkout@v4
 
       - name: Run type checking
-        run: mypy --ignore-missing-imports alot/errors.py alot/__init__.py alot/utils/cached_property.py
+        run: 'nix build --print-build-logs .\#checks.x86_64-linux.types'
 
 
   nix-flake:
@@ -61,13 +54,13 @@ jobs:
           - alot.man
 
     steps:
-    - name: Install Nix
-      uses: cachix/install-nix-action@v22
+      - name: Install Nix
+        uses: cachix/install-nix-action@v22
 
-    - uses: actions/checkout@v4
+      - uses: actions/checkout@v4
 
-    - name: Build the ${{ matrix.derivation }} derivation
-      run: 'nix build --print-build-logs .\#${{ matrix.derivation }}'
+      - name: Build the ${{ matrix.derivation }} derivation
+        run: 'nix build --print-build-logs .\#${{ matrix.derivation }}'
 
 
   generated-docs: