Fix path error

Author: niranjanyardi

cobalt/testing/tools/process_size_artifacts.sh

@@ -45,7 +45,9 @@ for artifact_dir in size_artifacts/size_artifacts_*; do
 
     echo "Running Check binary size for $PLATFORM"
     chmod +x "$RUNNER_PATH"
-    python3 "$RUNNER_PATH"
+    pushd "$(dirname "$RUNNER_PATH")"
+    python3 "$(basename "$RUNNER_PATH")"
+    popd
 
     find_file "perf_results.json" "$artifact_dir" "SIZES_PATH" || continue