test: wait for links and metrics in prometheus_rabbitmq_federation_collector_SUITE (backport #12642) (backport #12647)

[mergify]

Attempt to fix more test flakes in CI

---

This is an automatic backport of pull request #12642 done by Mergify.

---

This is an automatic backport of pull request #12647 done by Mergify.

[mergify]

Cherry-pick of 3575fb5 has failed:

On branch mergify/bp/v3.13.x/pr-12647
Your branch is up to date with 'origin/v3.13.x'.

You are currently cherry-picking commit 3575fb5492.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   deps/rabbitmq_prometheus/test/prometheus_rabbitmq_federation_collector_SUITE.erl

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally