Update pyupgrade requirement from ~=2.11 to ~=2.12

Updates the requirements on [pyupgrade](https://github.com/asottile/pyupgrade) to permit the latest version.
- [Release notes](https://github.com/asottile/pyupgrade/releases)
- [Commits](asottile/pyupgrade@v2.11.0...v2.12.0)

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

requirements-dev.txt

@@ -3,5 +3,5 @@ black==20.08b1
 packaging==20.9
 pre-commit~=2.12
 PyGithub~=1.54
-pyupgrade~=2.11
+pyupgrade~=2.12
 yamllint~=1.26