fix(lint): resolve action-validator failure on language-version-detect

- Remove unsupported `deprecated: true` from language-version-detect/action.yml
  (deprecation already communicated via description field)
- Scope action-validator pre-commit hook to workflow and action.yml files only
- Make missing pre-commit a hard error in lint-actions target

.pre-commit-config.yaml

@@ -99,3 +99,4 @@ repos:
     rev: v0.8.0
     hooks:
       - id: action-validator
+        files: '(^\.github/workflows/.*\.ya?ml$|.*/action\.ya?ml$)'