Merge branch '5.3' into 5.4

* 5.3:
  [Tests] Remove some unused fixtures
  added missing translations for portuguese [#43726]
  [HttpClient][Mime] Add correct IDN flags for IDNA2008 compliance
  properly parse quoted strings tagged with !!str
  do not merge label classes into expanded choice labels
  [Serializer] PropertyNormalizer - return unique (i.e. filter duplicate ) attributes in extractAttributes function

Author: derrabus

Resources/translations/validators.pt.xlf

@@ -394,6 +394,14 @@
                 <source>This value is not a valid CSS color.</source>
                 <target>Este valor não é uma cor de CSS válida.</target>
             </trans-unit>
+            <trans-unit id="102">
+                <source>This value is not a valid CIDR notation.</source>
+                <target>Este valor não é uma notação CIDR válida.</target>
+            </trans-unit>
+            <trans-unit id="103">
+                <source>The value of the netmask should be between {{ min }} and {{ max }}.</source>
+                <target>O valor da máscara de rede deve estar entre {{ min }} e {{ max }}.</target>
+            </trans-unit>
         </body>
     </file>
 </xliff>