[url_launcher] Replace deprecated renderView #143449
Description
'renderView' is deprecated and shouldn't be used. Consider using
RendererBinding.renderViews instead as the binding may manage multiple RenderViews. This feature was
deprecated after v3.10.0-12.0.pre. Try replacing the use of the deprecated member with the replacement.
I'm not sure if this is in 3.10 or 3.13 from the message; currently it's test-only code, so we could wait until 3.13 is our min-min version to fix this, since test-only fixes don't need to spread through the client ecosystem.