Minor version bumps should be mostly trivial: Change version and hash, package that into commit+PR (ckeck guidelines on that!) and that’s it most of the time.
The harder part is QA; ensuring it still works as expected. Therefore, even just testing update PRs as they come in would be a great help.
If the code change is trivial and a user of the package said it still works for them, a commiter coming along is likely convinced of the PR’s quality and just merges it.
It’s super easy to contribute to Nixpkgs in a meaningful manner :)