Catch specific exception types in XunitLoggerProvider

Address code review feedback by catching specific exception types
(InvalidOperationException and NullReferenceException) instead of
catching all exceptions. This helps distinguish between expected
disposal-related exceptions and genuine errors.

Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>

Author: Copilot

tests/Common/Utils/XunitLoggerProvider.cs

@@ -38,11 +38,16 @@ public void Log<TState>(
             {
                 output.WriteLine(sb.ToString());
             }
-            catch
+            catch (InvalidOperationException)
             {
                 // Ignore exceptions from xUnit's TestOutputHelper when the test has already completed.
                 // Background work may continue logging after xUnit has disposed the test context.
             }
+            catch (NullReferenceException)
+            {
+                // xUnit v3 may throw NullReferenceException in TestOutputHelper.QueueTestOutput()
+                // when the internal queue has been torn down after test completion.
+            }
         }
 
         public bool IsEnabled(LogLevel logLevel) => true;