Removes the test added as part of https://github.com/quarkusio/quarkus/pull/48751

Unfortunately, I couldn't find a way to provide a reliable test. When multiple repositories, including mirrors) are configured (such as in our CI), it gets even more complicated to figure out when a tmp file needs to be removed. Until a better approach is found, I think it'd better to remove this test.

I'm adding the same backport labels #48751 has.