add: actionlint

Author: a5chin

.github/workflows/actionlint.yml

@@ -0,0 +1,18 @@
+name: Lint GitHub Actions workflows
+
+on:
+  pull_request:
+    paths:
+      - .github/workflows/*.yml
+      - .github/actionlint.yml
+      - .github/actionlint-matcher.json
+
+jobs:
+  actionlint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Check workflow files
+        uses: reviewdog/action-actionlint@v1

.github/workflows/gh-deploy.yml

@@ -33,12 +33,13 @@ jobs:
         uses: ./.github/actions/setup-python-with-uv
 
       - name: Generate cache id
-        run: echo "cache_id=$(date --utc '+%V')" >> $GITHUB_ENV
+        id: cache
+        run: echo "id=$(date --utc '+%V')" >> "$GITHUB_OUTPUT"
 
       - name: Save cache
         uses: actions/cache@v5
         with:
-          key: mkdocs-material-${{ env.cache_id }}
+          key: mkdocs-material-${{ steps.cache.outputs.id }}
           path: .cache
           restore-keys: mkdocs-material-