Merge branch '2.0' into 3.0

* 2.0:
  TASK: Adjust versions of github actions
  TASK: Adjust target branch to run ci for from main to 2.0
  Make nullability explicit

# Conflicts:
#	.github/workflows/build.yml

Author: mficzel

.github/workflows/build.yml

@@ -3,12 +3,10 @@ name: build
 on:
   push:
     branches:
-      - 'main'
-      - 'neos9'
+      - '3.0'
   pull_request:
     branches:
-      - 'main'
-      - 'neos9'
+      - '3.0'
 
 jobs:
   test:

Classes/Infrastructure/DeepL/DeepLTranslationService.php

@@ -221,7 +221,7 @@ protected function getDeeplAuthenticationKey(): DeepLAuthenticationKey
      *
      * @return string
      */
-    public static function getEntryIdentifier(string $text, string $targetLanguage, string $sourceLanguage = null): string
+    public static function getEntryIdentifier(string $text, string $targetLanguage, ?string $sourceLanguage = null): string
     {
         return sha1($text . $targetLanguage . $sourceLanguage);
     }
@@ -249,7 +249,7 @@ protected function getBrowser(): Browser
     protected function createRequest(
         string $endpoint,
         string $method = 'GET',
-        string $body = null
+        ?string $body = null
     ): ServerRequestInterface {
         $deeplAuthenticationKey = $this->getDeeplAuthenticationKey();
         $baseUri = $deeplAuthenticationKey->isFree ? $this->settings['baseUriFree'] : $this->settings['baseUri'];