Currently we set
async=true;defer=true;. However, most browsers support async so defer should be no longer set. This is recommended behavior and ensures a browser won't prefer
async (which be bad for performance).
Should be updated in generated tracking code and in docs. Only
async=true should be set.
it seems like GA also only sets async, but not defer (https://github.com/matomo-org/matomo/issues/16189)