Update pygithub requirement from <1.59,>=1.54 to >=1.54,<1.60 in /req…

…uirements (#232)

Update pygithub requirement in /requirements

Updates the requirements on [pygithub](https://github.com/pygithub/pygithub) to permit the latest version.
- [Release notes](https://github.com/pygithub/pygithub/releases)
- [Changelog](https://github.com/PyGithub/PyGithub/blob/main/doc/changes.rst)
- [Commits](PyGithub/PyGithub@v1.54...v1.59.0)

---
updated-dependencies:
- dependency-name: pygithub
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements/base.txt

@@ -2,7 +2,7 @@
 # -----------------------
 
 GitPython>=3.1,<3.2
-PyGithub>=1.54,<1.59
+PyGithub>=1.54,<1.60
 PyQt5>=5.15,<5.16
 pyqt5ac>=1.2,<1.3
 python-slugify>=4.0,<8.1