Clarify ClassCleanupBehavior.EndOfClass usage syntax in MSTEST0034 documentation (#47581)

* Initial plan

* Clarify ClassCleanupBehavior.EndOfClass usage syntax

Co-authored-by: Youssef1313 <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: Youssef1313 <[email protected]>

Author: Copilot

docs/core/testing/mstest-analyzers/mstest0034.md

@@ -34,7 +34,7 @@ Without using  `ClassCleanupBehavior.EndOfClass`, the `[ClassCleanup]` will by d
 
 ## How to fix violations
 
-Use `ClassCleanupBehavior.EndOfClass` with the `[ClassCleanup]`.
+Use `[ClassCleanup(ClassCleanupBehavior.EndOfClass)]`.
 
 ## When to suppress warnings