Add '.kokoro/test.sh' to the ignored files list

Author: sofisl

owlbot.py

@@ -22,6 +22,7 @@
   ".github/release-please.yml",
   '.kokoro/publish.sh',
   '.kokoro/release/publish.cfg',
+  '.kokoro/test.sh',
   '.github/workflows/ci.yaml',
   '.github/workflows/issues-no-repro.yaml'
 ])