Can not publish to GitHub Actions Marketplace

[anttiharju]

https://github.com/anttiharju/compare-changes-action/releases/tag/v0.7.16 ends up in "Server Error":

[anttiharju]

Could always move to the pattern github uses https://github.com/actions/checkout

but they move where the v0 etc. tag points to, which is a bit mad as far as I can see vs. using a branch

[anttiharju]

• Fix Remove cold-start CI dependency on action repo being in a usable state #152 first

[anttiharju]

Note #164