CI: Fix OS error in perf job script

Author: maxknv

ci/jobs/performance_tests.py

@@ -170,7 +170,6 @@ def run_test(
         if res != 0:
             with open(f"{results_path}/{test_name}-err.log", "w") as f:
                 f.write(err)
-            err = Shell.get_output(f"echo \"{err}\" | grep '{test_name}\t'")
         with open(f"{results_path}/{test_name}-raw.tsv", "w") as f:
             f.write(out)
         with open(f"{results_path}/wall-clock-times.tsv", "a") as f: