Bump pygit2 from 1.12.2 to 1.13.2 (#167)

Bumps [pygit2](https://github.com/libgit2/pygit2) from 1.12.2 to 1.13.2.
- [Changelog](https://github.com/libgit2/pygit2/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/libgit2/pygit2/compare/v1.12.2...v1.13.2)

---
updated-dependencies:
- dependency-name: pygit2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

requirements.txt

@@ -4,7 +4,7 @@ html5lib==1.1
 Markdown==3.4.4
 mwparserfromhell==0.6.5
 pycparser==2.21
-pygit2==1.12.2
+pygit2==1.13.2
 python-dateutil==2.8.2
 python-frontmatter==1.0.0
 python-liquid==1.10.0