Proposed commit message

The TestGroup_Go subtests are known to be flaky, likely due to small assertion timeouts. On Windows, these assertions take longer to complete than on Unix systems. This change relaxes the timeouts to improve stability.

I ran the tests locally with x/tools/cmd/stress and it appears to have stabilized:

13m30s: 105896 runs so far, 0 failures, 32 active

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.

How to test this PR locally

On a windows box:

$ cd filebeat/input/filestream/internal/task 
$ go test -c
$ go run golang.org/x/tools/cmd/stress@latest -p 32 ./task.test -test.run TestGroup_Go -test.v

Related issues

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

  ---

  This is an automatic backport of pull request fix(tests): relax TestGroup_Go timeouts #42862 done by Mergify.