There is a new pull request by sgn against master on the void-packages repository

https://github.com/sgn/void-packages travis-speed-up-changed-template-script
https://github.com/void-linux/void-packages/pull/22228

travis/changed_templates: filter by git itself
- Use plumbing git-diff-tree(1) instead of porcelain git-diff(1)
- Disable rename detection, gains some speed up and fix missing template
  with name-status Renamed and Copied.
- Use "--diff-filter" to filter by Git itself.
- Tell Git to only check 'srcpkgs/*/template', this glob will only look
  into template file inside direct sub-directory of srcpkgs
- With all of those options, we don't need a grep and a pipe

A patch file from https://github.com/void-linux/void-packages/pull/22228.patch is attached