.NET: Skip failing IT

[rogerbarreto]

Motivation and Context

Integration Tests failing consistently and blocking further .NET PR's merge.

[xUnit.net 00:00:19.41]         RESPONSE: 
  Failed Microsoft.Agents.AI.Workflows.Declarative.IntegrationTests.MediaInputTest.ValidateFileUrlAsync(fileSource: "https://sample-files.com/downloads/images/jpg/web_"···, mediaType: "image/jpeg") [18 s]
  Error Message:
   Assert.NotEmpty() Failure: Collection was empty
  Stack Trace:
     at Microsoft.Agents.AI.Workflows.Declarative.IntegrationTests.MediaInputTest.<ValidateFileAsync>d__8.MoveNext() in D:\a\agent-framework\agent-framework\dotnet\tests\Microsoft.Agents.AI.Workflows.Declarative.IntegrationTests\MediaInputTest.cs:line 84
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Agents.AI.Workflows.Declarative.IntegrationTests.MediaInputTest.<ValidateFileUrlAsync>d__4.MoveNext() in D:\a\agent-framework\agent-framework\dotnet\tests\Microsoft.Agents.AI.Workflows.Declarative.IntegrationTests\MediaInputTest.cs:line 32
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
  Standard Output Messages:
 File: https://sample-files.com/downloads/images/jpg/web_optimized_1200x800_97kb.jpg

[Copilot]

Pull request overview

This PR addresses consistently failing integration tests by skipping a test case that's blocking .NET PR merges. The test is failing due to issues in the agent service API when processing image URLs.

Key Changes:

• Added Skip attribute to the ImageReference test case in ValidateFileUrlAsync with an explanation of the failure