Merge branch '4.3' into 4.4

* 4.3:
  fix PHP 5.6 compatibility
  [Cache] fixed TagAwareAdapter returning invalid cache
  Add plus character `+` to legal mime subtype
  Make Symfony\Contracts\Service\Test\ServiceLocatorTest abstract
  bug #33942 [DI] Add extra type check to php dumper
  [Dotenv] search variable values in ENV first then env file
  [PropertyInfo] Respect property name case when guessing from public method name
  [VarDumper] fix resetting the "bold" state in CliDumper
  Missing argument in method_exists
  SCA: added missing break in a loop

Author: xabbuh

Test/ServiceLocatorTest.php

@@ -15,9 +15,9 @@
 use Psr\Container\ContainerInterface;
 use Symfony\Contracts\Service\ServiceLocatorTrait;
 
-class ServiceLocatorTest extends TestCase
+abstract class ServiceLocatorTest extends TestCase
 {
-    public function getServiceLocator(array $factories)
+    protected function getServiceLocator(array $factories)
     {
         return new class($factories) implements ContainerInterface {
             use ServiceLocatorTrait;