Add yamllint, ansible-lint, and a syntax check

scripts/check.sh runs all three and CI calls the same script. ansible.cfg keeps Ansible's temp and Galaxy caches inside the checkout so the checks work when $HOME is read-only.

.gitea/workflows/check.yml

@@ -0,0 +1,18 @@
+name: check
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - name: Install linters
+        run: pip install ansible-core ansible-lint yamllint
+      - name: Run checks
+        run: ./scripts/check.sh