chore: Remove invalid config in Postfix `master.cf` (#2272)

This was all introduced by the original project author early on, no explanation for it.

- None of the paths they use as `argv` values exist.
- `uucp` doesn't seem relevant to the project. No justification for it, no issues or PRs in project history or codebase.

See associated PR for further details and linked resources.

target/postfix/master.cf

@@ -67,19 +67,6 @@ lmtp      unix  -       -       n       -       -       lmtp
 anvil     unix  -       -       y       -       1       anvil
 scache    unix  -       -       y       -       1       scache
 
-maildrop  unix  -       n       n       -       -       pipe
-  flags=DRhu user=vmail argv=/usr/bin/maildrop -d ${recipient}
-uucp      unix  -       n       n       -       -       pipe
-  flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
-ifmail    unix  -       n       n       -       -       pipe
-  flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
-bsmtp     unix  -       n       n       -       -       pipe
-  flags=Fq. user=bsmtp argv=/usr/lib/bsmtp/bsmtp -t$nexthop -f$sender $recipient
-scalemail-backend unix	-	n	n	-	2	pipe
-  flags=R user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store ${nexthop} ${user} ${extension}
-mailman   unix  -       n       n       -       -       pipe
-  flags=FR user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py
-  ${nexthop} ${user}
 sender-cleanup unix n   -       -       -       0       cleanup
   -o syslog_name=postfix/sender-cleanup
   -o header_checks=pcre:/etc/postfix/maps/sender_header_filter.pcre