Updated actions/checkout to v4

[ckunki]

No description provided.

[Nicoretti]

Sadly, this change is not trivial due to the fact that the upload and download semantics have changed, affecting overwrites and resulting in different download URLs. With v4, if you push the same artifact name multiple times, it gets uploaded multiple times. However, the validity seems to depend on the last "overwrite." If one is unlucky, the wrong download URL will be used on the other end, resulting in broken or non-existing artifacts, etc.

[ckunki]

Sadly, this change is not trivial due to the fact that the upload and download semantics have changed, affecting overwrites and resulting in different download URLs. With v4, if you push the same artifact name multiple times, it gets uploaded multiple times. However, the validity seems to depend on the last "overwrite." If one is unlucky, the wrong download URL will be used on the other end, resulting in broken or non-existing artifacts, etc.

Do you propose to switch back to v3 then?

[Nicoretti]

@ckunki we also can push forward this pr, but then we likely need to change the upload and download strategy we are using right now. If this will be addressed in this PR to I'll happy to merge it!