fix: don't create index concurrently in migration

it doesn't work if the command is run in a migration, which is the case
when we use alembic.

migrations/007_add_logo_annotation_server_type_index.py

@@ -4,7 +4,7 @@
 
 def migrate(migrator: Migrator, database: pw.Database, *, fake=False):
     migrator.sql(
-        "CREATE INDEX CONCURRENTLY IF NOT EXISTS logo_annotation_server_type ON logo_annotation (server_type)"
+        "CREATE INDEX IF NOT EXISTS logo_annotation_server_type ON logo_annotation (server_type)"
     )