squid-deb-proxy missed bookworm

I'll skip it from our playbooks for now, but we really should get it back into testing and make a backport to bookworm. It's a useful service.

Issues:

1. #932501 - broken apparmor. Probably shouldn't be RC, as this isn't enabled by default.
2. #999646 - writing messages to stdout, breaking APT consumers. This has been fixed upstream.

It's a native package. Upstream github is quite far ahead of Debian. Ubuntu has taken some patches from there, and others that are still pending upstream review. The right answer may be to just upload the patches Ubuntu is using for now?