chore(db): drop redundant idx_webhook_on_workflow_id_block_id index (#4809)

Removed because (workflow_id, block_id) is a left-prefix of idx_webhook_on_workflow_id_block_id_updated_at_desc, which fully covers it. The dropped index was non-unique and enforced no constraint.

Author: waleedlatif1

packages/db/migrations/0221_secret_hannibal_king.sql

@@ -0,0 +1 @@
+DROP INDEX "idx_webhook_on_workflow_id_block_id";