fix(amazonq): utg findSourceFileByContent passes wrong context #5873

## Problem
Using extractClasses with path as file content incorrectly, so always
returns empty list.

## Solution
Fix the call.
fix #5864

Author: Will-ShaoHua

packages/core/src/codewhisperer/util/supplementalContext/utgUtils.ts

@@ -129,7 +129,7 @@ async function findSourceFileByContent(
 
     throwIfCancelled(cancellationToken)
 
-    testElementList.push(...extractClasses(editor.document.fileName, languageConfig.classExtractionPattern))
+    testElementList.push(...extractClasses(testFileContent, languageConfig.classExtractionPattern))
 
     throwIfCancelled(cancellationToken)