Wait for used controllers in test setup (backport #1519)

[mergify]

Otherwise initial controller switches may fail

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This is an automatic backport of pull request #1519 done by Mergify.

[mergify]

Cherry-pick of bcbcac7 has failed:

On branch mergify/bp/humble/pr-1519
Your branch is up to date with 'origin/humble'.

You are currently cherry-picking commit bcbcac7.
  (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)

Changes to be committed:
	modified:   ur_robot_driver/test/integration_test_force_mode.py

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	deleted by us:   ur_robot_driver/test/integration_test_passthrough_controller.py
	deleted by us:   ur_robot_driver/test/integration_test_scaled_joint_controller.py

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