fix(ci): use script file instead of inline Python in playbook-schema

Inline Python code with f-strings and set literals caused YAML parsing
errors. Replaced with reference to scripts/validate_playbook_schema.py.

Refs: #461

.gitea/workflows/validate-config.yaml

@@ -112,23 +112,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+      - name: Install PyYAML
+        run: pip install pyyaml
       - name: Validate playbook structure
-        run: |
+        run: python3 scripts/validate_playbook_schema.py
-          python3 -c "
-import yaml, sys, glob
-required_keys = {'name', 'description'}
-for f in glob.glob('playbooks/*.yaml'):
-    with open(f) as fh:
-        try:
-            data = yaml.safe_load(fh)
-            if not isinstance(data, dict):
-                print(f'ERROR: {f} is not a YAML mapping')
-                sys.exit(1)
-            missing = required_keys - set(data.keys())
-            if missing:
-                print(f'WARNING: {f} missing keys: {missing}')
-            print(f'OK: {f}')
-        except yaml.YAMLError as e:
-            print(f'ERROR: {f}: {e}')
-            sys.exit(1)
-"

scripts/validate_playbook_schema.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+"""Validate playbook YAML files have required keys."""
+import yaml
+import sys
+import glob
+
+required_keys = {'name', 'description'}
+
+for f in glob.glob('playbooks/*.yaml'):
+    with open(f) as fh:
+        try:
+            data = yaml.safe_load(fh)
+            if not isinstance(data, dict):
+                print(f'ERROR: {f} is not a YAML mapping')
+                sys.exit(1)
+            missing = required_keys - set(data.keys())
+            if missing:
+                print(f'WARNING: {f} missing keys: {missing}')
+            print(f'OK: {f}')
+        except yaml.YAMLError as e:
+            print(f'ERROR: {f}: {e}')
+            sys.exit(1)