fix(deps): update dependency icalendar to v6

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
icalendar (changelog)	~=5.0 -> ~=6.0

---

Release Notes

collective/icalendar (icalendar)

v6.0.1

Compare Source

New features:

• Added end, start, duration, DTSTART, DUE, and DURATION attributes to Event components. See Issue 662_.
• Added end, start, duration, and DTSTART attributes to Journal components. See Issue 662_.

Bug fixes:

• Fix a few __all__ variables.
• Added missing docs folder to distribution packages. See Issue 712 <https://github.com/collective/icalendar/issues/712>_.

.. _Issue 662: https://github.com/collective/icalendar/issues/662

v6.0.0

Compare Source

Minor changes:

• Add __all__ variable to each modules in icalendar package
• Improve test coverage.
• Adapt test_with_doctest.py to correctly run on Windows.
• Measure branch coverage when running tests.
• Export Component base class for typing

New features:

• Use pyproject.toml file instead of setup.py

Bug fixes:

• Fix link to stable release of tox in documentation.
• Fix a bad bytes replace in unescape_char.
• Handle ValueError in vBinary.from_ical.
• Ignore the BOM character in incorrectly encoded ics files.

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.