fix(pageserver): queue stopped error should be ignored during create timeline

[skyzh]

Problem

close #9730

The test case tests if anything goes wrong during pageserver restart + during timeline creation not complete. Therefore, queue is stopped error is normal in this case, except that it should be categorized as a shutdown error instead of a real error.

Summary of changes

• More comments for the test case.
• Queue stopped error will now be forwarded as CreateTimelineError::ShuttingDown.

[github-actions]

5490 tests run: 5264 passed, 0 failed, 226 skipped (full report)

---

Code coverage* (full report)

• functions: 31.5% (7931 of 25167 functions)
• lines: 49.6% (62843 of 126583 lines)

* collected from Rust tests only

---

_{The comment gets automatically updated with the latest test results
b7b2b53 at 2024-11-18T19:01:18.136Z :recycle:}

[skyzh]

ahh... seems like wait_for_tenant_active is not the right function to use

[skyzh]

removed wait for tenant to start and assume the test case also tests the case where the timeline doesn't initialize before restart. ready for review.