lint: fix pub.dev lint_core warnings

Author: cybex-dev

lib/src/core/enums/call_event_type.dart

@@ -11,8 +11,8 @@ enum CallEventType {
         return '~';
       case CallEventType.remove:
         return '-';
-      default:
-        return '?';
+      // default:
+      //   return '?';
     }
   }
 }

lib/src/method_channel/web_callkit_method_channel.dart

@@ -612,9 +612,9 @@ class MethodChannelWebCallkit extends WebCallkitPlatform {
         _dismissNotification(result.uuid);
         break;
 
-      default:
-        printDebug("Unknown action: ${result.action}", tag: tag);
-        break;
+      // default:
+      //   printDebug("Unknown action: ${result.action}", tag: tag);
+      //   break;
     }
   }