some fixes for windows and python 3.9 w/ burnettk

spiffworkflow-backend/src/spiffworkflow_backend/models/message_instance.py

@@ -59,7 +59,7 @@ class MessageInstanceModel(SpiffworkflowBaseDBModel):
     updated_at_in_seconds: int = db.Column(db.Integer)
     created_at_in_seconds: int = db.Column(db.Integer)
 
-    message_correlations: dict | None = None
+    message_correlations: Optional[dict] = None
 
     @validates("message_type")
     def validate_message_type(self, key: str, value: Any) -> Any:

spiffworkflow-backend/src/spiffworkflow_backend/services/file_system_service.py

@@ -60,8 +60,9 @@ class FileSystemService:
     @staticmethod
     def workflow_path(spec: ProcessModelInfo) -> str:
         """Workflow_path."""
-        process_model_path = os.path.join(FileSystemService.root_path(), spec.id)
-        # process_group_path = FileSystemService.process_group_path_for_spec(spec)
+        process_model_path = os.path.join(
+            FileSystemService.root_path(), spec.id_for_file_path()
+        )
         return process_model_path
 
     @staticmethod