fix: Adjust schedule for pw_mcjax_benchmark_recipe (GoogleCloudPlatform#1108)

This change adjusts the schedule for the `pw_mcjax_benchmark_recipe` DAG to:
- Restrict execution to the PROD Composer environment (prevent non-PROD triggers).
- Run outside peak hours to keep cluster capacity available.

Author: RUEI4341

dags/maxtext_pathways/pw_mcjax_dags.py

@@ -27,6 +27,7 @@
 from airflow.providers.google.cloud.operators.kubernetes_engine import GKEStartPodOperator
 from kubernetes.client import models as k8s
 
+from dags import composer_env
 from dags.common import test_owner
 from dags.maxtext_pathways.configs import commands as cmds
 from dags.maxtext_pathways.configs import parameters as ui_params
@@ -261,7 +262,7 @@ def wait_workload_complete(
 with models.DAG(
     dag_id=RECIPE_NAME,
     start_date=datetime.datetime(2025, 1, 1),
-    schedule_interval="0 10 * * *",
+    schedule_interval="0 21 * * *" if composer_env.is_prod_env() else None,
     catchup=False,
     default_args={
         "retries": 0,