Document collection expression limitation - elements require special unwrapping

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

Author: Copilot

src/Microsoft.CodeAnalysis.NetAnalyzers/tests/Microsoft.CodeAnalysis.NetAnalyzers.UnitTests/Microsoft.NetCore.Analyzers/Tasks/DoNotUseNonCancelableTaskDelayWithWhenAnyTests.cs

@@ -297,7 +297,9 @@ async Task M()
 ");
         }
 
-        // Note: Collection expression support is handled via ICollectionExpressionOperationWrapper
-        // but explicit test is omitted due to test framework complexities with C# 12 features
+        // Note: Collection expression elements are wrapped in operation nodes that require
+        // special unwrapping logic. The analyzer includes ICollectionExpressionOperationWrapper
+        // handling, but collection expression elements may be wrapped differently than
+        // array initializer elements, requiring additional investigation to properly unwrap them.
     }
 }