EHStreamingResumeTests.ResumeAfterInactivityNotInCache times out on net8.0 #10661

ServiceBus.Tests.Streaming.EHStreamingResumeTests.ResumeAfterInactivityNotInCache timed out in the Azure Event Hubs provider tests on net8.0 in two consecutive CI runs for the documentation-only PR #10654 and its merge commit.

The test waits 30 seconds in StreamingDiagnosticObserver.WaitForStreamInactiveAsync and fails with System.Threading.Tasks.TaskCanceledException:

at TestExtensions.StreamingDiagnosticObserver.WaitForStreamInactiveAsync(...) in StreamingDiagnosticObserver.cs:line 281
at Tester.StreamingTests.StreamingResumeTests.ResumeAfterInactivityImpl(...) in StreamingResumeTests.cs:line 62
at Tester.StreamingTests.StreamingResumeTests.ResumeAfterInactivityNotInCache() in StreamingResumeTests.cs:line 31

Runs:

• PR run: https://github.com/dotnet/orleans/actions/runs/32192103789/job/95888446344
• Merge commit run: https://github.com/dotnet/orleans/actions/runs/32221563925/job/95972860068

In both runs, the corresponding net10.0 Event Hubs job passed. The changed file in #10654 was documentation only (docs/site/src/content/docs/streaming/streams-programming-apis.md), so this failure is unrelated to that change.