Update pre-commit requirement from ~=2.14 to ~=2.15

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/master/CHANGELOG.md)
- [Commits](pre-commit/pre-commit@v2.14.0...v2.15.0)

---
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==21.8b0
 packaging==21.0
-pre-commit~=2.14
+pre-commit~=2.15
 PyGithub~=1.54
 pyupgrade~=2.25
 yamllint~=1.26