⬆️ Bump spatie/icalendar-generator from 2.8.1 to 2.9.0

Bumps [spatie/icalendar-generator](https://github.com/spatie/icalendar-generator) from 2.8.1 to 2.9.0.
- [Release notes](https://github.com/spatie/icalendar-generator/releases)
- [Changelog](https://github.com/spatie/icalendar-generator/blob/main/CHANGELOG.md)
- [Commits](spatie/icalendar-generator@2.8.1...2.9.0)

---
updated-dependencies:
- dependency-name: spatie/icalendar-generator
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]