Revert "Secrets: Refactor data_key_id out of the encoded secure value payload" (#112034)

Revert "Secrets: Refactor data_key_id out of the encoded secure value payload…"

This reverts commit acad92864e.

pkg/storage/secret/encryption/testdata/postgres--encrypted_value_create-create.sql

@@ -3,7 +3,6 @@ INSERT INTO "secret_encrypted_value" (
   "name",
   "version",
   "encrypted_data",
-  "data_key_id",
   "created",
   "updated"
 ) VALUES (
@@ -11,7 +10,6 @@ INSERT INTO "secret_encrypted_value" (
   'n1',
   1,
   '[115 101 99 114 101 116]',
-  'test-data-key-id',
   1234,
   5678
 );