Update pre-commit requirement from ~=2.19 to ~=2.20

Updates the requirements on [pre-commit](https://github.com/pre-commit/pre-commit) to permit the latest version.
- [Release notes](https://github.com/pre-commit/pre-commit/releases)
- [Changelog](https://github.com/pre-commit/pre-commit/blob/main/CHANGELOG.md)
- [Commits](pre-commit/pre-commit@v2.19.0...v2.20.0)

---
updated-dependencies:
- dependency-name: pre-commit
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements-dev.txt

@@ -1,7 +1,7 @@
 -r requirements-test.txt
 black==22.6.0
 packaging==21.3
-pre-commit~=2.19
+pre-commit~=2.20
 PyGithub~=1.55
 pyupgrade~=2.34
 yamllint~=1.26