fix(mfa): fix can't dismiss mfa guard for ARK delete

Because:

* can't dismiss mfa guard for ARK delete

This commit:

* makes mfa guard for ARK delete dismissable.

Closes #FXA-12470

Author: MagentaManifold

packages/fxa-settings/src/components/Settings/UnitRowRecoveryKey/index.tsx

@@ -131,11 +131,12 @@ export const UnitRowRecoveryKey = () => {
             );
           }}
         >
-          <MfaGuard requiredScope="recovery_key">
+          <MfaGuard
+            requiredScope="recovery_key"
+            onDismissCallback={async () => hideModal()}
+          >
             <Modal
-              onDismiss={() => {
-                hideModal();
-              }}
+              onDismiss={hideModal}
               onConfirm={() => {
                 setIsDeleting(true);
                 deleteRecoveryKey();