fix: enable batch operations in alembic for sqlite unique constraints

l4d2web/alembic/env.py

@@ -25,6 +25,7 @@ def run_migrations_offline() -> None:
         target_metadata=target_metadata,
         literal_binds=True,
         dialect_opts={"paramstyle": "named"},
+        render_as_batch=True
     )
 
     with context.begin_transaction():
@@ -41,7 +42,11 @@ def run_migrations_online() -> None:
     )
 
     with connectable.connect() as connection:
-        context.configure(connection=connection, target_metadata=target_metadata)
+        context.configure(
+            connection=connection, 
+            target_metadata=target_metadata,
+            render_as_batch=True
+        )
 
         with context.begin_transaction():
             context.run_migrations()

l4d2web/alembic/versions/b2c684fddbd3_make_server_port_unique.py

@@ -21,12 +21,14 @@ depends_on: Union[str, Sequence[str], None] = None
 def upgrade() -> None:
     """Upgrade schema."""
     # ### commands auto generated by Alembic - please adjust! ###
-    op.create_unique_constraint(None, 'servers', ['port'])
+    with op.batch_alter_table('servers', schema=None) as batch_op:
+        batch_op.create_unique_constraint(batch_op.f('uq_servers_port'), ['port'])
     # ### end Alembic commands ###
 
 
 def downgrade() -> None:
     """Downgrade schema."""
     # ### commands auto generated by Alembic - please adjust! ###
-    op.drop_constraint(None, 'servers', type_='unique')
+    with op.batch_alter_table('servers', schema=None) as batch_op:
+        batch_op.drop_constraint(batch_op.f('uq_servers_port'), type_='unique')
     # ### end Alembic commands ###