feat(BackedEnumTypeSpacing): Add SlevomatCodingStandard.Classes.BackedEnumTypeSpacing sniff (#3496958)

Author: klausi

coder_sniffer/Drupal/ruleset.xml

@@ -117,6 +117,8 @@
   <rule ref="PSR2.Namespaces.NamespaceDeclaration"/>
   <rule ref="PSR2.Namespaces.UseDeclaration"/>
 
+  <!-- SlevomatCodingStandard sniffs -->
+  <rule ref="SlevomatCodingStandard.Classes.BackedEnumTypeSpacing"/>
   <rule ref="SlevomatCodingStandard.ControlStructures.RequireNullCoalesceOperator"/>
   <rule ref="SlevomatCodingStandard.PHP.ShortList"/>
   <rule ref="SlevomatCodingStandard.TypeHints.DeclareStrictTypes">