[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/asottile/add-trailing-comma: v3.0.1 → v3.1.0](asottile/add-trailing-comma@v3.0.1...v3.1.0)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -51,6 +51,6 @@ repos:
         - --py36-plus
 
 - repo: https://github.com/asottile/add-trailing-comma
-  rev: v3.0.1
+  rev: v3.1.0
   hooks:
     - id: add-trailing-comma