Make PHP use all the RAM when not in 'web' container

Currently the default memory allocated per process defaults to 196MB (`memory_limit`), unless specified otherwise in the composer.json file.
While it's understandable with the `web` process type, it doesn't really make sense for other process types (a scheduled job running in a one-off, for example).

It would be better to make it use all the RAM and stick to `pm.max_children=1` in such cases.