ci: validate GitHub workflows/Dependabot config

.github/workflows/tools-config-check.yml

@@ -0,0 +1,42 @@
+name: Tools configuration
+
+on:
+  push:
+    branches: ["main"]
+    paths:
+      - ".github/workflows/*.yml"
+      - ".github/workflows/*.yaml"
+      - ".github/dependabot.yml"
+      - ".github/dependabot.yaml"
+      - "pyproject.toml"
+      - "poetry.lock"
+      - "Makefile"
+  pull_request:
+    branches: ["main"]
+    paths:
+      - ".github/workflows/*.yml"
+      - ".github/workflows/*.yaml"
+      - ".github/dependabot.yml"
+      - ".github/dependabot.yaml"
+      - "pyproject.toml"
+      - "poetry.lock"
+      - "Makefile"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: actions/setup-python@v6
+        with:
+          python-version: "3.14"
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install poetry
+          poetry install --only dev --no-root
+      - run: make tools-config-check

Makefile

@@ -10,7 +10,12 @@ lint:
 typecheck:
 	poetry run dmypy run -- src tests
 
-pre-commit: fmt lint typecheck
+pre-commit: fmt lint typecheck tools-config-check
+
+tools-config-check:
+	poetry run actionlint
+	poetry run check-jsonschema --builtin-schema vendor.github-workflows .github/workflows/*.y*ml
+	poetry run check-jsonschema --builtin-schema vendor.dependabot .github/dependabot.y*ml
 
 test:
 	poetry run pytest tests