Publieke statistieken verbergen van /about en about.json

[merefield (Robert)]

@jrgong

We still want to keep it accessible for theme components

which use … about.json
https://github.com/discourse/discourse-stat-banner/blob/b6728301187d4dbf32152cd1d0232844c0d76e85/javascripts/discourse/components/stat-banner.gjs#L182