Make sure tests are actually run when some of them are selected

[conradoplg]

Motivation

In some cases we select one or a group of tests to be run. For example, in the .yml files to regenerate the cached state, and in #2633 to run some tests with fake activation heights.

However, it's possible that renaming these tests can cause the tests to be no longer run, and we could not notice that (since cargo test will happily return 0 indicating success even if no tests are run).

Come up with a way to detect if that happens and fail. (For example, we could grep the output and check if something has actually run)

Examples

Here are some example tickets:

• Fake activation heights test is not running in CI #3673
• Release Blocker: Stop skipping the cached sync tests in CI #2402

[mpguerra]

Hey team! Please add your planning poker estimate with ZenHub @conradoplg @dconnolly @jvff @oxarbitrage @teor2345 @upbqdn

[teor2345]

We don't know how to do this easily, we should fix missing tests when they come up.

We could search for "run 0 tests" in the logs.

[teor2345]

PR #4710 fixes part of this ticket, but only for a single workflow