Update and Fix itsycal

updates itsycal to new version
fixes "Error: It seems the symlink source is not there: '/opt/homebrew-cask/Caskroom/itsycal/0.8.10/Itsycal 0.8.10/Itsycal.app'" when installing
Merge pull request #7374 from plessbd/itsycal

Update and Fix itsycal