FrankenPHP build slowdown

[Walter-o]

hello!

At line 80 in docker/entrypoint-frankenphp.sh
which reads:
chown -R www-data:www-data /app/public/var

It slows my server down for like 20-40 seconds before resuming.
And this is on every restart of the docker container.

I just verified it doesn't happen on non-frankenphp builds.

The reason why this isn't a merge request is because i don't know if this line of code is like a cardhouse.
Someone with good knowledge of the codebase has to make a judgement.