Feature Freeze announcement and pre-release cleanup

The feature freeze announcement should be done 8 weeks before the release to inform subsystem maintainers about the upcoming feature freeze and to discuss potential blockers in the respective subsystems. This announcement is done on GitHub (22.05 example). It's also a good idea to cross-post this to Discourse to raise awareness about the upcoming freeze (22.05 example).

People and teams will be pinged in this issue. The list of people and teams pinged is generated from the teams list in nixpkgs. The script to generate the pings is: ./maintainers/feature-freeze-teams.pl in nixpkgs. The script needs a GitHub username and a token to read the teams from the NixOS org. Instructions are provided as a comment in the script.

You might need to add a comment that pings people again because GitHub seems to limit the amount of people that can be pinged per post.

Pre-release cleanup

The pre-release cleanup consists of multiple small cleanups to keep the release secure throughout its lifecycle while also maintaining some level of cleanliness.

• Remove attributes that we know we will not be able to support, especially if there is a stable alternative. E.g. Check that our Linux kernels’ projected end-of-life are after our release projected end-of-life.

  Many EOL dates are also tracked by the endoflife.date project and some packages might need closer supervision in that regard.

  The "Picking up the garbage" project tracks problematic packages that should be removed.

• Attributes that can also be safely removed are packages that were broken for more than 2 years.