refactor: make playwright service's default command be to run the tests

compose.yml

@@ -49,5 +49,4 @@ services:
     image: benefits_client:playwright
     volumes:
       - ./tests/playwright:/playwright
-    # https://code.visualstudio.com/docs/remote/create-dev-container#_use-docker-compose
-    entrypoint: sleep infinity
+    command: ./run.sh