add(test): Check that scan task removes keys, unify scan task acceptance tests, and add test to CI

[arya2]

Motivation

We want to check that the scan task removes keys after receiving RemoveKeys messages.

Closes #8286
Closes #8274
Closes #8259

PR Author Checklist

Check before marking the PR as ready for review:

• Will the PR name make sense to users?
• Does the PR have a priority label?
• Have you added or updated tests?
• Is the documentation up to date?

For significant changes:

• Is there a summary in the CHANGELOG?
• Can these changes be split into multiple PRs?

If a checkbox isn't relevant to the PR, mark it as done.

Solution

• Deletes the scans_for_new_key test now
• Renames scan_subscribe_results test to scan_task_commands
• Calls scan_task.remove_keys() from scan_task_commands test
• Waits for the scan task to drop the results sender, then:
  • Empties the results channel
  • Asserts that the first error is a Disconnected error

Related Cleanups:

• Updates remove_keys() to accept a Vec instead of a slice.

Review

Anyone can review.

Reviewer Checklist

Check before approving the PR:

• Does the PR scope match the ticket?
• Are there enough tests to make sure it works? Do the tests cover the PR motivation?
• Are all the PR blockers dealt with?
  PR blockers can be dealt with in new tickets or PRs.

And check the PR Author checklist is complete.

[arya2]

Thank you @gustavovalverde for finding the issue!

[gustavovalverde]

CI is good to go!

[oxarbitrage]

Looks good to me, thank you!

[gustavovalverde]

utACK