Final release of Granite 6?

### Problem

There are some unreleased changes in Granite 6 since its current latest release: https://github.com/elementary/granite/commits/master/

### Proposal

As we go forward to Granite 7 to 9, we might want to publish a final release of Granite 6, which is in `master` and `deb-packaging-focal` branches, and officially declares as EOL?

### Prior Art (Optional)

_No response_