[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/rbubley/mirrors-prettier: 0ee178619d696787ca73d210cc191d720868c631 → ef4a397f916211b4a39ccf9d3d9cbb6562157251](rbubley/mirrors-prettier@0ee1786...ef4a397)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -24,7 +24,7 @@ repos:
       - id: blacken-docs
 
   - repo: https://github.com/rbubley/mirrors-prettier
-    rev: 0ee178619d696787ca73d210cc191d720868c631 # frozen: v3.9.6
+    rev: ef4a397f916211b4a39ccf9d3d9cbb6562157251  # frozen: v3.9.9
     hooks:
       - id: prettier
         files: \.(css|md|yml|yaml)