fix: install python yaml module for YAML validation

.gitea/workflows/syntax-check.yml

@@ -52,5 +52,10 @@ jobs:
       - name: Validate YAML configuration
         run: |
           echo "Checking YAML files..."
+          if command -v apk >/dev/null 2>&1; then
+            apk add --no-cache py3-yaml
+          elif command -v apt-get >/dev/null 2>&1; then
+            apt-get update && apt-get install -y python3-yaml
+          fi
           python3 -c "import yaml; yaml.safe_load(open('bitbucket-pipelines.yml'))"
           python3 -c "import yaml; yaml.safe_load(open('.gitea/workflows/syntax-check.yml'))"