Remove _codeql_detected_source_root from tracking, add to .gitignore

Co-authored-by: lijy91 <3889523+lijy91@users.noreply.github.com>

Author: Copilot

.gitignore

@@ -9,6 +9,7 @@ build-macos/
 build-ohos/
 build-windows/
 cmake-build-debug/
+_codeql_detected_source_root
 
 # Generated test binaries and object files
 *.o