.NET: CI: DurableTask.IntegrtionTests often fail on TTL check with TaskCancelled blocking merges

@cgillum is already working on this.

Since Jun 25, 2026.

The error in the logs is of the form:

```
[xUnit.net 00:00:30.25] 2026-01-27T00:23:18.5212839+00:00 [Microsoft.DurableTask.Agents.TTLResetTestAgent.6f2c49d66cd244cbbf99ab196db9e078] LogTTLEntityExpired [@dafx-ttlresettestagent@6f2c49d66cd244cbbf99ab196db9e078] Entity expired and deleted due to TTL. Expiration time: 2026-01-27T00:23:18.4797690Z
Failed Microsoft.Agents.AI.DurableTask.IntegrationTests.TimeToLiveTests.EntityTTLResetsOnInteractionAsync [30 s]
Error Message:
System.Threading.Tasks.TaskCanceledException : A task was canceled.
Stack Trace:
at Microsoft.Agents.AI.DurableTask.AgentRunHandle.ReadAgentResponseAsync(CancellationToken cancellationToken) in /home/runner/work/agent-framework/agent-framework/dotnet/src/Microsoft.Agents.AI.DurableTask/AgentRunHandle.cs:line 77
at Microsoft.Agents.AI.DurableTask.DurableAIAgentProxy.RunCoreAsync(IEnumerable`1 messages, AgentSession session, AgentRunOptions options, CancellationToken cancellationToken) in /home/runner/work/agent-framework/agent-framework/dotnet/src/Microsoft.Agents.AI.DurableTask/DurableAIAgentProxy.cs:line 70
at Microsoft.Agents.AI.DurableTask.IntegrationTests.TimeToLiveTests.EntityTTLResetsOnInteractionAsync() in /home/runner/work/agent-framework/agent-framework/dotnet/tests/Microsoft.Agents.AI.DurableTask.IntegrationTests/TimeToLiveTests.cs:line 128
--- End of stack trace from previous location ---
Standard Output Messages:
2026-01-27T00:23:09.6127429+00:00 [Microsoft.Extensions.Hosting.Internal.Host] Starting Hosting starting
2026-01-27T00:23:09.6698652+00:00 [Microsoft.Hosting.Lifetime] Application started. Press Ctrl+C to shut down.
2026-01-27T00:23:09.6751127+00:00 [Microsoft.Hosting.Lifetime] Hosting environment: Production
2026-01-27T00:23:09.6751582+00:00 [Microsoft.Hosting.Lifetime] Content root path: /home/runner/work/agent-framework/agent-framework/dotnet/tests/Microsoft.Agents.AI.DurableTask.IntegrationTests/bin/Release/net10.0
2026-01-27T00:23:09.6753150+00:00 [Microsoft.Extensions.Hosting.Internal.Host] Started Hosting started
2026-01-27T00:23:09.6799845+00:00 [Microsoft.DurableTask] StartingTaskHubWorker Durable Task gRPC worker starting and connecting to localhost:8080.
2026-01-27T00:23:09.6932490+00:00 [Microsoft.Agents.AI.DurableTask.DefaultDurableAgentClient] LogSignallingAgent Signalling agent with session ID '@dafx-ttlresettestagent@6f2c49d66cd244cbbf99ab196db9e078'
2026-01-27T00:23:09.8038539+00:00 [Microsoft.DurableTask] EstablishedWorkItemConnection Sidecar work-item streaming connection established.
2026-01-27T00:23:09.8838747+00:00 [Microsoft.Agents.AI.DurableTask.DefaultDurableAgentClient] LogStartPollingForResponse Polling agent with session ID '@dafx-ttlresettestagent@6f2c49d66cd244cbbf99ab196db9e078' for response with correlation ID 'a3f6e5434fd0499985aa91b55ceb6d8e'
2026-01-27T00:23:09.9287617+00:00 [Microsoft.DurableTask.Agents.TTLResetTestAgent.6f2c49d66cd244cbbf99ab196db9e078] LogAgentRequest [@dafx-ttlresettestagent@6f2c49d66cd244cbbf99ab196db9e078] Request: [user] Hello!
2026-01-27T00:23:12.4792203+00:00 [Microsoft.DurableTask.Agents.TTLResetTestAgent.6f2c49d66cd244cbbf99ab196db9e078] LogAgentResponse [@dafx-ttlresettestagent@6f2c49d66cd244cbbf99ab196db9e078] Response: [assistant] Hello! 😊 How can I assist you today? (Input tokens: 19, Output tokens: 11, Total tokens: 30)
2026-01-27T00:23:12.4839071+00:00 [Microsoft.DurableTask.Agents.TTLResetTestAgent.6f2c49d66cd244cbbf99ab196db9e078] LogTTLExpirationTimeUpdated [@dafx-ttlresettestagent@6f2c49d66cd244cbbf99ab196db9e078] TTL expiration time updated to 2026-01-27T00:23:18.4797690Z
2026-01-27T00:23:12.4842773+00:00 [Microsoft.DurableTask.Agents.TTLResetTestAgent.6f2c49d66cd244cbbf99ab196db9e078] LogTTLDeletionScheduled [@dafx-ttlresettestagent@6f2c49d66cd244cbbf99ab196db9e078] TTL deletion signal scheduled for 2026-01-27T00:23:18.4797690Z
2026-01-27T00:23:18.5209426+00:00 [Microsoft.DurableTask.Agents.TTLResetTestAgent.6f2c49d66cd244cbbf99ab196db9e078] LogTTLDeletionCheck [@dafx-ttlresettestagent@6f2c49d66cd244cbbf99ab196db9e078] TTL deletion check running. Expiration time: 2026-01-27T00:23:18.4797690Z, Current time: 2026-01-27T00:23:18.5032590Z
2026-01-27T00:23:18.5212839+00:00 [Microsoft.DurableTask.Agents.TTLResetTestAgent.6f2c49d66cd244cbbf99ab196db9e078] LogTTLEntityExpired [@dafx-ttlresettestagent@6f2c49d66cd244cbbf99ab196db9e078] Entity expired and deleted due to TTL. Expiration time: 2026-01-27T00:23:18.4797690Z
```

I'm going to temporarily disable them to unblock merges