Call prepare_data() after setup_environment() for XLA (#19181)

Co-authored-by: awaelchli <[email protected]>

Author: jerrymannil

src/lightning/pytorch/trainer/trainer.py

@@ -935,17 +935,16 @@ def _run(
 
         _verify_loop_configurations(self)
 
-        # hook
-        log.debug(f"{self.__class__.__name__}: preparing data")
-        self._data_connector.prepare_data()
-
         # ----------------------------
         # SET UP THE TRAINER
         # ----------------------------
         log.debug(f"{self.__class__.__name__}: setting up strategy environment")
         self.strategy.setup_environment()
         self.__setup_profiler()
 
+        log.debug(f"{self.__class__.__name__}: preparing data")
+        self._data_connector.prepare_data()
+
         call._call_setup_hook(self)  # allow user to set up LightningModule in accelerator environment
         log.debug(f"{self.__class__.__name__}: configuring model")
         call._call_configure_model(self)