Merge branch '5.3' into 5.4

* 5.3:
  Try making tests a bit less transient
  Fix CI on macos-11
  [Serializer] Fix denormalizing custom class in UidNormalizer
  [Config] In XmlUtils, avoid converting from octal every string starting with a 0
  Make RateLimiter resilient to timeShifting

Tests/ApplicationTest.php

@@ -883,6 +883,9 @@ public function testRenderExceptionLineBreaks()
         $this->assertStringMatchesFormatFile(self::$fixturesPath.'/application_renderexception_linebreaks.txt', $tester->getDisplay(true), '->renderException() keep multiple line breaks');
     }
 
+    /**
+     * @group transient-on-windows
+     */
     public function testRenderAnonymousException()
     {
         $application = new Application();
@@ -906,6 +909,9 @@ public function testRenderAnonymousException()
         $this->assertStringContainsString('Dummy type "class@anonymous" is invalid.', $tester->getDisplay(true));
     }
 
+    /**
+     * @group transient-on-windows
+     */
     public function testRenderExceptionStackTraceContainsRootException()
     {
         $application = new Application();