remove deprecated features

MessageCatalogue.php

@@ -30,12 +30,8 @@ class MessageCatalogue implements MessageCatalogueInterface, MetadataAwareInterf
      * @param string $locale   The locale
      * @param array  $messages An array of messages classified by domain
      */
-    public function __construct(?string $locale, array $messages = [])
+    public function __construct(string $locale, array $messages = [])
     {
-        if (null === $locale) {
-            @trigger_error(sprintf('Passing "null" to the first argument of the "%s" method has been deprecated since Symfony 4.4 and will throw an error in 5.0.', __METHOD__), E_USER_DEPRECATED);
-        }
-
         $this->locale = $locale;
         $this->messages = $messages;
     }

Tests/MessageCatalogueTest.php

@@ -23,17 +23,6 @@ public function testGetLocale()
         $this->assertEquals('en', $catalogue->getLocale());
     }
 
-    /**
-     * @group legacy
-     * @expectedDeprecation Passing "null" to the first argument of the "Symfony\Component\Translation\MessageCatalogue::__construct" method has been deprecated since Symfony 4.4 and will throw an error in 5.0.
-     */
-    public function testGetNullLocale()
-    {
-        $catalogue = new MessageCatalogue(null);
-
-        $this->assertNull($catalogue->getLocale());
-    }
-
     public function testGetDomains()
     {
         $catalogue = new MessageCatalogue('en', ['domain1' => [], 'domain2' => [], 'domain2+intl-icu' => [], 'domain3+intl-icu' => []]);

Translator.php

@@ -130,10 +130,6 @@ public function addResource(string $format, $resource, string $locale, string $d
             $domain = 'messages';
         }
 
-        if (null === $locale) {
-            @trigger_error(sprintf('Passing "null" to the third argument of the "%s" method has been deprecated since Symfony 4.4 and will throw an error in 5.0.', __METHOD__), E_USER_DEPRECATED);
-        }
-
         $this->assertValidLocale($locale);
 
         $this->resources[$locale][] = [$format, $resource, $domain];