- Run the `update.yml` workflow on the triggered branch, replace the
job matrix with a conditional step that runs update on nixos-24.05.
- Added a `cancel-in-progress` concurrency group.
- Disabled committing in PR action (using negative add-paths).
- Rename workflow to simply "update"
- Drop the DeterminateSystems/update-flake-lock action
- Instead use `nix flake update --commit-lock-file`
- Also use `generate-files`'s `--commit` option
- Use peter-evans/create-pull-request to open a PR
This directly reads the package.json file in pkgs.rust-analyzer.src in
order to generate the list of options for rust-analyzer.
This avoids the need for a generator script, and makes sure that it is
always in sync.
