Merge branch '5.2' into 5.x

* 5.2:
  Update .github/workflows/tests.yml
  Don't call class_exists() on null
  Added and improved Bulgarian translations
  PHP 8.1 must not cause the build to fail (yet)
  Add _run_tests bash function
  Add a GitHub Action for tests against PHP 8.1
  [HttpClient] fix adding query string to relative URLs with scoped clients
  [Security] Added Ukrainian translations

Author: derrabus

Compiler/CheckTypeDeclarationsPass.php

@@ -88,8 +88,13 @@ protected function processValue($value, bool $isRoot = false)
             return parent::processValue($value, $isRoot);
         }
 
-        if (!$this->autoload && !class_exists($class = $value->getClass(), false) && !interface_exists($class, false)) {
-            return parent::processValue($value, $isRoot);
+        if (!$this->autoload) {
+            if (!$class = $value->getClass()) {
+                return parent::processValue($value, $isRoot);
+            }
+            if (!class_exists($class, false) && !interface_exists($class, false)) {
+                return parent::processValue($value, $isRoot);
+            }
         }
 
         if (ServiceLocator::class === $value->getClass()) {