Fix invalid circleci config file (#335)

Author: tyrone-yu

.circleci/config.yml

@@ -66,7 +66,6 @@ workflows:
       - path-filtering/filter:
           base-revision: main
           config-path: .circleci/test.yml
-          tag: "3.9"
           mapping: |
             psi/.* build-and-run true
             bazel/.* build-and-run true