Remove codeql artifact and add to gitignore

Co-authored-by: darkautism <3898040+darkautism@users.noreply.github.com>

Author: Copilot

.gitignore

@@ -15,3 +15,6 @@ bin/
 *.a
 *.so
 *.so.*
+
+# CodeQL artifacts
+_codeql_detected_source_root