chore: remove invalid unique on column

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: gfyrag

internal/storage/bucket/migrations/41-add-schema/up.sql

@@ -4,7 +4,7 @@ do $$
 
 		create table schemas (
 			ledger varchar,
-			version text not null unique,
+			version text not null,
 			created_at timestamp without time zone not null default now(),
 			primary key (ledger, version)
 		);