[8.x](backport #41223) Skip flaky tests TestFileWatcher and TestGroup_Go

[mergify]

Proposed commit message

This PR skips two flaky tests from the Filestream input, the tests are:

• TestFileWatcher (issue: TestFileWatcher/does_not_emit_events_for_empty_files/emits_a_create_event_once_something_is_written_to_the_empty_file #41209)
• TestGroup_Go (issue: TestGroup_Go - not all goroutines finished/"task.Group: semaphore acquire failed, was the task group closed? err: context canceled #41218)

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

## Disruptive User Impact
## Author's Checklist
## How to test this PR locally

Related issues

• Relates TestFileWatcher/does_not_emit_events_for_empty_files/emits_a_create_event_once_something_is_written_to_the_empty_file #41209
• Relates TestGroup_Go - not all goroutines finished/"task.Group: semaphore acquire failed, was the task group closed? err: context canceled #41218

## Use cases
## Screenshots
## Logs

---

This is an automatic backport of pull request #41223 done by Mergify.

[botelastic]

This pull request doesn't have a Team:<team> label.