Ensure languages in tests have a label set (#1384)

This ensures that the language configuration passes schema validation.

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Co-authored-by: Alexander Varwijk <327697+Kingdutch@users.noreply.github.com>

Author: chrfritsch

tests/src/Kernel/GraphQLTestBase.php

@@ -82,11 +82,13 @@ protected function setUp(): void {
     ConfigurableLanguage::create([
       'id' => 'fr',
       'weight' => 1,
+      'label' => 'French',
     ])->save();
 
     ConfigurableLanguage::create([
       'id' => 'de',
       'weight' => 2,
+      'label' => 'German',
     ])->save();
 
     $this->builder = new ResolverBuilder();