Revert "[Dashboard] Start the new dashboard (#9860)" (#10116)

This reverts commit 739933e5b8.

python/ray/services.py

@@ -1162,14 +1162,8 @@ def start_dashboard(require_dashboard,
             raise ValueError("The given dashboard port {}"
                              " is already in use".format(port))
 
-    if "RAY_USE_NEW_DASHBOARD" in os.environ:
-        dashboard_dir = "new_dashboard"
-    else:
-        dashboard_dir = "dashboard"
-
     dashboard_filepath = os.path.join(
-        os.path.dirname(os.path.abspath(__file__)), dashboard_dir,
-        "dashboard.py")
+        os.path.dirname(os.path.abspath(__file__)), "dashboard/dashboard.py")
     command = [
         sys.executable,
         "-u",
@@ -1404,23 +1398,6 @@ def start_raylet(redis_address,
     if load_code_from_local:
         start_worker_command += ["--load-code-from-local"]
 
-    # Create agent command
-    agent_command = [
-        sys.executable,
-        "-u",
-        os.path.join(
-            os.path.dirname(os.path.abspath(__file__)),
-            "new_dashboard/agent.py"),
-        "--redis-address={}".format(redis_address),
-        "--node-manager-port={}".format(node_manager_port),
-        "--object-store-name={}".format(plasma_store_name),
-        "--raylet-name={}".format(raylet_name),
-        "--temp-dir={}".format(temp_dir),
-    ]
-
-    if redis_password is not None and len(redis_password) != 0:
-        agent_command.append("--redis-password={}".format(redis_password))
-
     command = [
         RAYLET_EXECUTABLE,
         "--raylet_socket_name={}".format(raylet_name),
@@ -1449,9 +1426,6 @@ def start_raylet(redis_address,
     if start_initial_python_workers_for_first_job:
         command.append("--num_initial_python_workers_for_first_job={}".format(
             resource_spec.num_cpus))
-    if "RAY_USE_NEW_DASHBOARD" in os.environ:
-        command.append("--agent_command={}".format(
-            subprocess.list2cmdline(agent_command)))
     if config.get("plasma_store_as_thread"):
         # command related to the plasma store
         plasma_directory, object_store_memory = determine_plasma_store_config(