build(deps-dev): bump pygithub from 2.6.0 to 2.8.1

Bumps [pygithub](https://github.com/pygithub/pygithub) from 2.6.0 to 2.8.1.
- [Release notes](https://github.com/pygithub/pygithub/releases)
- [Changelog](https://github.com/PyGithub/PyGithub/blob/main/doc/changes.rst)
- [Commits](https://github.com/pygithub/pygithub/compare/v2.6.0...v2.8.1)

---
updated-dependencies:
- dependency-name: pygithub
  dependency-version: 2.8.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

pyproject.toml

@@ -142,7 +142,7 @@ dev = [
     "isort==7.0.0",
     "mypy==1.19.1",
     "mypy-protobuf==3.6.0",
-    "PyGithub==2.6.0",
+    "PyGithub==2.8.1",
     "bump-my-version==1.2.4",
     # type stubs for mypy
     "types-backports==0.1.3",