Retire polaris-reg-test script (#1219)

Author: liamzwbao

Diff for: regtests/Dockerfile

@@ -40,7 +40,7 @@ WORKDIR /home/spark/polaris
 COPY ./regtests/setup.sh /home/spark/polaris/regtests/setup.sh
 COPY ./regtests/pyspark-setup.sh /home/spark/polaris/regtests/pyspark-setup.sh
 COPY ./client/python /home/spark/polaris/client/python
-COPY ./regtests/polaris-reg-test /home/spark/polaris/polaris
+COPY ./polaris /home/spark/polaris/polaris
 COPY ./regtests/requirements.txt /tmp/
 
 RUN python3 -m venv /home/spark/polaris/polaris-venv && \