Make up missing model help texts for job timeout.

awx/main/models/inventory.py

@@ -952,6 +952,7 @@ class InventorySourceOptions(BaseModel):
     timeout = models.IntegerField(
         blank=True,
         default=0,
+        help_text=_("The amount of time (in seconds) to run before the task is canceled."),
     )
     verbosity = models.PositiveIntegerField(
         choices=INVENTORY_UPDATE_VERBOSITY_CHOICES,