fix(backend): create pricetier enum before migration

backend/alembic/versions/f1a2b3c4d5e6_add_async_pricing_jobs_and_snapshot_fields.py

@@ -20,11 +20,15 @@ depends_on: Union[str, Sequence[str], None] = None
 
 
 def upgrade() -> None:
+    bind = op.get_bind()
+    price_tier_enum = sa.Enum("BUDGET", "MID", "PREMIUM", "LUXURY", name="pricetier")
+    price_tier_enum.create(bind, checkfirst=True)
+
     op.add_column(
         "products",
         sa.Column(
             "price_tier",
-            sa.Enum("BUDGET", "MID", "PREMIUM", "LUXURY", name="pricetier"),
+            price_tier_enum,
             nullable=True,
         ),
     )