fix(db): Delete legacy credential_vault_library_deleted purge job (#6284)

With the refactor in version 99, the credential_vault_library_deleted
table was renamed to credential_vault_generic_library_deleted, but its
corresponding purge job was not removed from the job table, leading to
an error: "job credential_vault_library_deleted_items_table_purge not
registered on scheduler".

This commit deletes the legacy job entry. The new job that takes over
the legacy one is
credential_vault_generic_library_deleted_items_table_purge.

internal/db/schema/migrations/oss/postgres/102/01_credential_vault_library_deleted_purge_job.sql

@@ -0,0 +1,12 @@
+-- Copyright (c) HashiCorp, Inc.
+-- SPDX-License-Identifier: BUSL-1.1
+
+begin;
+  -- The credential_vault_library_deleted table was renamed to
+  -- credential_vault_generic_library_deleted in
+  -- 99/01_credential_vault_library_refactor.up.sql, but the corresponding
+  -- legacy purge job was not deleted. This migration deletes that legacy job.
+  -- The new job that takes over the legacy one is
+  -- credential_vault_generic_library_deleted_items_table_purge.
+  delete from job where name = 'credential_vault_library_deleted_items_table_purge';
+commit;