Update ext.manifest

Author: AGulev

webview/ext.manifest

@@ -1,6 +1,9 @@
 name: WebViewExternal
 
 platforms:
+  arm64-osx:
+    context:
+        frameworks: ["WebKit"]
   x86_64-osx:
     context:
         frameworks: ["WebKit"]
@@ -15,4 +18,4 @@ platforms:
 
   x86_64-ios:
     context:
-        frameworks: ["WebKit"]
+        frameworks: ["WebKit"]