tests(helpers): move wait functions

[chronolaw]

Summary

KAG-5421

The parameter strategy of vwait_until_no_common_workers() is never used, perhaps we should remove it and clean the code where call it.

Checklist

• The Pull Request has tests
• A changelog file has been created under changelog/unreleased/kong or skip-changelog label added on PR if changelog is unnecessary. README.md
• There is a user-facing docs PR against https://github.com/Kong/docs.konghq.com - PUT DOCS PR HERE

Issue reference

Fix #[issue number]

[team-gateway-bot]

Cherry-pick failed for master, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally.

git remote add upstream https://github.com/kong/kong-ee
git fetch upstream master
git worktree add -d .worktree/cherry-pick-13692-to-master-to-upstream upstream/master
cd .worktree/cherry-pick-13692-to-master-to-upstream
git checkout -b cherry-pick-13692-to-master-to-upstream
ancref=$(git merge-base 2ba3de19741d416f7c8eafac277e5fc6ccf74d7a 45b22e38ab00dcdbdfba7c169099e45dff235ad8)
git cherry-pick -x $ancref..45b22e38ab00dcdbdfba7c169099e45dff235ad8