run tests for operators which are relevant to the changes in the PR

right now we are running some tests for any change in the repository. Those tests are for just for zookeeper operator. In case we change some other operator logic, these tests are irrelevant.
we should only run the tests related to that operator or no tests in case we don't have any for that operator. We need to ensure that:

- CI run tests that are relevant to the changes done in the PR
- PR status provide feedback on which tests are being run
- Provide documentation/examples on how to add tests for an operator

In all cases, the PR checks should provide information around which tests have been run for a certain PR. To enable users to write tests for their own operators that can live in this repository.

Start by examining the repository's existing CI checks and the current Zookeeper operator test setup. Determine how changed operators can be identified and how test selection and reporting should work. Done means relevant checks run for each change, PR status identifies them, and contributors have examples for adding operator tests.

Written by the indexing model from the issue text.