build(deps): bump holidays from 0.50 to 0.51

Bumps [holidays](https://github.com/vacanza/python-holidays) from 0.50 to 0.51.
- [Release notes](https://github.com/vacanza/python-holidays/releases)
- [Changelog](https://github.com/vacanza/python-holidays/blob/dev/CHANGES)
- [Commits](vacanza/python-holidays@v0.50...v0.51)

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

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

requirements.txt

@@ -4,7 +4,7 @@
 #
 #    pip-compile requirements.in
 #
-holidays==0.50
+holidays==0.51
     # via -r requirements.in
 python-dateutil==2.9.0.post0
     # via