Bump pygithub from 2.6.1 to 2.8.1

Bumps [pygithub](https://github.com/pygithub/pygithub) from 2.6.1 to 2.8.1.
- [Release notes](https://github.com/pygithub/pygithub/releases)
- [Changelog](https://github.com/PyGithub/PyGithub/blob/main/doc/changes.rst)
- [Commits](PyGithub/PyGithub@v2.6.1...v2.8.1)

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

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

Author: dependabot[bot]

poetry.lock

@@ -23,7 +23,7 @@ marshmallow = "4.0.1"
 marshmallow-dataclass = "8.7.1"
 click = "8.1.7"
 PyYAML = "6.0.2"
-PyGithub = "2.6.1"
+PyGithub = "2.8.1"
 single-source = "0.4.0"
 cryptography = ">=45.0.0"