Flake update CI is failing

[MattSturgeon]

The flake.lock update workflow is failing with permission errors.

The permissions in the workflow file are fine, however in your repo settings you need to enable "Allow GitHub Actions to create and approve pull requests":

This setting is found at repo -> settings -> Actions -> General -> Workflow permissions.
i.e. here.

cc @R1kaB3rN @GloriousEggroll

[MattSturgeon]

Failed again this week: https://github.com/Open-Wine-Components/umu-launcher/actions/runs/13472766558/job/37648295752#step:4:731