LanguageUrlRewritingTest should not be setting the id of a language

Problem/Motivation

#2226533: Changes to the Language class due to the LanguageInterface (followup) was
diff --git a/core/modules/language/src/Tests/LanguageUrlRewritingTest.php b/core/modules/language/src/Tests/LanguageUrlRewritingTest.php
index 3701fb9..94dcd2f 100644
--- a/core/modules/language/src/Tests/LanguageUrlRewritingTest.php
+++ b/core/modules/language/src/Tests/LanguageUrlRewritingTest.php
@@ -52,7 +53,7 @@ protected function setUp() {
function testUrlRewritingEdgeCases() {
// Check URL rewriting with a non-installed language.
$non_existing = \Drupal::languageManager()->getDefaultLanguage();
- $non_existing->id = $this->randomMachineName();
+ $non_existing->setId($this->randomMachineName());
$this->checkUrl($non_existing, 'Path language is ignored if language is not installed.', 'URL language negotiation does not work with non-installed languages');

// Check that URL rewriting is not applied to subrequests.

but there is no setId()

Proposed resolution

handle this better, maybe in the create/new passing to the constructor.

Remaining tasks

User interface changes

No.

API changes

No.