Fix two flaky/broken functional tests

[spkane31]

What changed?

1. tests/task_queue_stats_test.go — Remove the t *testing.T field from taskQueueStatsSuite and replace all s.t usages with s.T(). Critically, fix validateDescribeWorkerDeploymentVersion to use a.NoError(err) instead of require.NoError(s.T(), err) inside the callback.
2. tests/xdc/history_replication_signals_and_updates_test.go — Fix pollWorkflowResult to handle errors from GetWorkflowExecutionHistory gracefully: return the error from the inner function, retry with a nil page token on transient errors (e.g. CurrentBranchChanged after conflict resolution), and abort cleanly when the context expires.

Why?

TestTaskQueueStats panic: Calling require.NoError(s.T(), err) inside an EventuallyWithT callback is unsafe. EventuallyWithT runs its callback in a separate goroutine on a ticker. If the outer test context expires and the test completes while this callback is still running, the require.NoError call invokes t.Fail() on a completed test, which panics the entire test binary with panic: Fail in goroutine after TestXxx has completed. The fix uses the CollectT-scoped a.NoError(err) so assertions are buffered and safe.

TestConflictResolutionGetResult hang/crash: pollWorkflowResult was calling responseInner.History.Events without checking if responseInner was nil. When GetWorkflowExecutionHistory returns an error (e.g. CurrentBranchChanged after conflict resolution resets the branch token), the response is nil, causing a nil pointer dereference that panics the goroutine. Because the goroutine crashed before sending to workflowResultCh, the main test goroutine blocked on <-workflowResultCh for the entire 30-minute CI timeout. The fix returns the error from the inner function and retries with a nil page token on transient errors, which allows the poll to succeed on the updated branch.

How did you test it?

• built
• run locally and tested manually
• covered by existing tests
• added new unit test(s)
• added new functional test(s)

Potential risks

The XDC fix changes pollWorkflowResult to retry indefinitely on any non-context error. If a non-transient error were to occur repeatedly, this could loop until the context expires rather than failing immediately. This is acceptable since the context timeout provides a hard bound, and the test failure message via c.t.s.NoError(ctx.Err(), ...) will make the root cause clear.

[spkane31]

We could add a lint to prevent embedding testing.T in new suites, this is causing issues for our tests

[stephanos]

Since #9536 decouples Env and assertions, that might already help a lot.

[stephanos]

This would be impossible with #9490 :D

[stephanos]

Why do we still need this one if the assertion checks it's 1 already?

[spkane31]

Removed