Change diff reference for admin UI check

[owi92]

Previously, this was pointing to the file from the base commit of the PR. While this works fine for PRs that target the "main" branch, when a PR targets any other branch, we'll want to reference the branch's name rather than a specific commit SHA.

At least that's what I think is going on.

[LukasKalbertodt]

Mh now I'm confused. I thought main was hardcoded and that's the problem, but the ref seems correct to me.

I looked at #1305 to figure this out and noticed that for your last force push, there is no admin UI comment anymore, so it works there. For that force push, graphql-inspector was instructed to compare 606d792c64d618460e116aa1397fc474c29e62ab and 119ad94e5bc598d53636d65eaf869f7d6ef753a4, which are the correct commits. And indeed, no diff was noticed. For your first push (the one that caused a comment to be posted), 45a70db39d13e3a45c7d11193016737ce92570c3 and 3d53a9fb3baf4eae6d216a7b096a7c149364df47 were compared. (You can see which commits were compared in the workflow log).

So I think the annoying comments we saw in the past weeks were just due to some random wrong base branches or whatever. I believe everything should be already fine the way it is now. #1295 also did not get a comment.

So we will just close this PR?

[owi92]

Closed as per the above comment