[pre-commit.ci] pre-commit autoupdate

updates:
- [github.com/asottile/pyupgrade: v2.29.1 → v2.31.0](asottile/pyupgrade@v2.29.1...v2.31.0)

Author: pre-commit-ci[bot]

.pre-commit-config.yaml

@@ -12,7 +12,7 @@ repos:
     -   id: flake8
         exclude: ^docs/conf.py
 -   repo: https://github.com/asottile/pyupgrade
-    rev: v2.29.1
+    rev: v2.31.0
     hooks:
     -   id: pyupgrade
         args: [--py36-plus]