build/ci: upgrade GitHub actions; add dependabot.yml 🤖

.github/dependabot.yml

@@ -0,0 +1,11 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: daily

.github/workflows/ci.yaml

@@ -17,11 +17,16 @@ jobs:
     name: Test on ${{ matrix.os }}
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
       - run: brew install coreutils gnu-sed
         # https://docs.github.com/en/actions/learn-github-actions/variables#detecting-the-operating-system
         # https://docs.github.com/en/actions/learn-github-actions/expressions
         if: runner.os == 'macOS'
       - run: test-cases/integration-test.sh
+      # https://remarkablemark.org/blog/2017/10/12/check-git-dirty/
+      - name: Check git dirty
+        run: |
+          git status --short
+          [ -z "$(git status --short)" ]

.github/workflows/lint.yaml

@@ -12,7 +12,12 @@ jobs:
     name: Lint
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
       - run: test-cases/lint.sh
+      # https://remarkablemark.org/blog/2017/10/12/check-git-dirty/
+      - name: Check git dirty
+        run: |
+          git status --short
+          [ -z "$(git status --short)" ]