fix(cli): do not pass the force-build flag to docker (#3641)

Author: Panaetius

renku/core/session/docker.py

@@ -356,6 +356,9 @@ def session_start_helper(consider_disk_request: bool):
                     environment["CHOWN_HOME"] = "yes"
                     environment["CHOWN_HOME_OPTS"] = "-R"
 
+                if "force_build" in kwargs:
+                    del kwargs["force_build"]
+
                 container = self.docker_client().containers.run(
                     image_name,
                     'jupyter notebook --NotebookApp.ip="0.0.0.0"'