[exim/exim] Remove obsolete AV scanners - Phase 2 (Issue #3210)

The following scanners no longer appear to be available and support will be removed.

Scanner Rationale f-prot6 Company closed 5 years ago f-prot6d Company closed 5 years ago sophie Company EOL-ed on-prem scan 3 years ago ( https://support.sophos.com/support/s/article/KBA-000002911?language=en_US ) drweb now uses rspamd/spamd or clamav interfaces ( https://cdn-download.drweb.com/pub/drweb/unix/mail/11.1/documentation/drweb-11.1-mss-unix-en.pdf )

**********************
Remaining AV Scanners.
**********************

Scanner URL clamav clamd ( https://docs.clamav.net/manual/Usage/Scanning.html#clamd ) f-secure avast avast-protocol ( https://repo.avcdn.net/linux-av/doc/avast-techdoc.pdf#%5B%7B%22num%22%3A29%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C0%2C841.89%2Cnull%5D ) sock socket access cmdline command line access

---
View it on Exim Forgejo ( https://code.exim.org/exim/exim/issues/3210 ) or reply to this email directly.