Fix DDP_SPAWN compatibility with bug_report_model.py (#6892)

(cherry picked from commit 87f0aea)

Author: ethanwharris

pl_examples/bug_report_model.py

@@ -126,12 +126,13 @@ def configure_optimizers(self):
 #  args = parser.parse_args(opt)
 
 
-def test_run():
+class TestModel(BoringModel):
+
+    def on_train_epoch_start(self) -> None:
+        print('override any method to prove your bug')
 
-    class TestModel(BoringModel):
 
-        def on_train_epoch_start(self) -> None:
-            print('override any method to prove your bug')
+def test_run():
 
     # fake data
     train_data = torch.utils.data.DataLoader(RandomDataset(32, 64))