Bump icalendar from 5.0.10 to 5.0.11 (#3058)

Bumps [icalendar](https://github.com/collective/icalendar) from 5.0.10 to 5.0.11.
- [Changelog](https://github.com/collective/icalendar/blob/master/CHANGES.rst)
- [Commits](collective/icalendar@v5.0.10...v5.0.11)

---
updated-dependencies:
- dependency-name: icalendar
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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