Pushing to main currently invalidates m1xxx cask checksums

[fwcd]

The release artifacts are currently overwritten even if the release already exists/the version hasn't changed. This leads to broken checksums in the Homebrew repository. We should fix this by e.g. not overwriting release assets or by automatically updating the Homebrew repository (e.g. via a repository_dispatch event? This would however muddle the clean separation between homebrew-fwcd polling for changes and this repository).