findMatchingRedirect produces same hash when langcode specified

Ran the test-only changes to confirm the test catches the bug. Looks like fixing this has caused knock on effects to other tests though. I'll look into it.

All the tests now seem to pass again except for this fail on the phpunit (next major) pipeline:

    1)
    Drupal\Tests\redirect\FunctionalJavascript\RedirectJavascriptTest::testRedirectUI
    Behat\Mink\Exception\ExpectationException: The string "Are you sure you
    want to delete the URL redirect from /web/non-existing?key=value to
    /web/node?" was not found anywhere in the HTML response of the current
    page.

however looking at the pipelines from other commits it looks like its unrelated to my code.