ci: add static analysis steps (format+lint+validate yaml)

.forgejo/workflows/ci.yml

@@ -0,0 +1,19 @@
+on: [push, pull_request]
+
+jobs:
+  static_analysis:
+    runs-on: runner-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v4
+        with:
+          python-version: '3.12'
+      - name: Linting & formatting check
+        uses: pre-commit/action@v3.0.1
+        with:
+          extra_args: ruff ruff-format --all-files
+      - name: Validate Yaml
+        uses: pre-commit/action@v3.0.1
+        with:
+          extra_args: check-yaml --all-files
+