Fix authorization level for reading compatibility level (#5225)

Author: carlesarnal

app/src/main/java/io/apicurio/registry/ccompat/rest/v6/impl/ConfigResourceImpl.java

@@ -87,7 +87,7 @@ private void updateCompatibilityLevel(CompatibilityLevelDto.Level level,
 
 
     @Override
-    @Authorized(style=AuthorizedStyle.None, level=AuthorizedLevel.Admin)
+    @Authorized(style = AuthorizedStyle.None, level = AuthorizedLevel.Read)
     public CompatibilityLevelParamDto getGlobalCompatibilityLevel() {
         logger.warn("The Confluent V6 compatibility API is deprecated and will be removed in future versions");
         return getCompatibilityLevel(() -> getStorage().getGlobalRule(RuleType.COMPATIBILITY).getConfiguration());