Update PR linting instructions (PhotonVision#2213)

## Description

Removes the checkbox for linting because it's easily invalidated by
later pushes. Also prints a link to the linting docs on CI failure.

## Meta

Merge checklist:
- [x] Pull Request title is [short, imperative
summary](https://cbea.ms/git-commit/) of proposed changes
- [x] The description documents the _what_ and _why_
- [ ] This PR has been
[linted](https://docs.photonvision.org/en/latest/docs/contributing/linting.html).
- [ ] If this PR changes behavior or adds a feature, user documentation
is updated
- [ ] If this PR touches photon-serde, all messages have been
regenerated and hashes have not changed unexpectedly
- [ ] If this PR touches configuration, this is backwards compatible
with settings back to v2025.3.2
- [ ] If this PR touches pipeline settings or anything related to data
exchange, the frontend typing is updated
- [ ] If this PR addresses a bug, a regression test for it is added

Author: samfreund

.github/pull_request_template.md

@@ -11,7 +11,6 @@
 Merge checklist:
 - [ ] Pull Request title is [short, imperative summary](https://cbea.ms/git-commit/) of proposed changes
 - [ ] The description documents the _what_ and _why_
-- [ ] This PR has been [linted](https://docs.photonvision.org/en/latest/docs/contributing/linting.html).
 - [ ] If this PR changes behavior or adds a feature, user documentation is updated
 - [ ] If this PR touches photon-serde, all messages have been regenerated and hashes have not changed unexpectedly
 - [ ] If this PR touches configuration, this is backwards compatible with settings back to v2025.3.2

.github/workflows/lint-format.yml

@@ -35,7 +35,14 @@ jobs:
       - name: Run
         run: wpiformat
       - name: Check output
-        run: git --no-pager diff --exit-code HEAD
+        run: |
+          set +e
+          git --no-pager diff --exit-code HEAD
+          exit_code=$?
+          if test "$exit_code" -ne "0"; then
+            echo "::error ::Linting failed. See https://docs.photonvision.org/en/latest/docs/contributing/linting.html"
+            exit $exit_code
+          fi
       - name: Generate diff
         run: git diff HEAD > wpiformat-fixes.patch
         if: ${{ failure() }}
@@ -56,9 +63,15 @@ jobs:
         with:
           java-version: 17
           distribution: temurin
-      - run: ./gradlew spotlessCheck
+      - run: |
+          set +e
+          ./gradlew spotlessCheck
+          exit_code=$?
+          if test "$exit_code" -ne "0"; then
+            echo "::error ::Linting failed. See https://docs.photonvision.org/en/latest/docs/contributing/linting.html"
+            exit $exit_code
+          fi
         name: Run spotless
-
   client-lint-format:
     name: "PhotonClient Lint and Formatting"
     defaults:
@@ -80,6 +93,20 @@ jobs:
       - name: Install Dependencies
         run: pnpm i --frozen-lockfile
       - name: Check Linting
-        run: pnpm run lint-ci
+        run: |
+          set +e
+          pnpm run lint-ci
+          exit_code=$?
+          if test "$exit_code" -ne "0"; then
+            echo "::error ::Linting failed. See https://docs.photonvision.org/en/latest/docs/contributing/linting.html"
+            exit $exit_code
+          fi
       - name: Check Formatting
-        run: pnpm run format-ci
+        run: |
+          set +e
+          pnpm run format-ci
+          exit_code=$?
+          if test "$exit_code" -ne "0"; then
+            echo "::error ::Linting failed. See https://docs.photonvision.org/en/latest/docs/contributing/linting.html"
+            exit $exit_code
+          fi