fix: revert "make migration idempotent" (#100)

This reverts commit 47b12ab, which is causing error "Migration failed. Reason: Hashes don't match for migrations '0007-add-public-to-buckets.sql'. This means that the scripts have changed since it was applied."

Author: thebengeu

migrations/tenant/0007-add-public-to-buckets.sql

@@ -1 +1 @@
-ALTER TABLE storage.buckets ADD COLUMN IF NOT EXISTS "public" boolean default false;
+ALTER TABLE storage.buckets ADD COLUMN "public" boolean default false;