Auto merge of #22549 - ferjm:create.wpt, r=jdm

Make create-wpt mach command use new manifest update implementation

- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #22525

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python/servo/testing_commands.py

@@ -928,12 +928,13 @@ testing/web-platform/mozilla/tests for Servo-only tests""" % reference_path)
 
         if not kwargs["no_run"]:
             p = create_parser_wpt()
-            args = ["--manifest-update"]
+            args = []
             if kwargs["release"]:
                 args.append("--release")
             args.append(test_path)
             wpt_kwargs = vars(p.parse_args(args))
             self.context.commands.dispatch("test-wpt", self.context, **wpt_kwargs)
+            self.context.commands.dispatch("update-manifest", self.context)
 
         if editor:
             proc.wait()