Remove Excision Mail (unmaintained since June 2022) (#3953)

- ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/3558
- `WARNING:awesome_lint.py: Excision Mail: last updated -380 days, 4:54:42.051740 ago, older than 365 days`
- Requires OpenBSD 6.6 which has reached end-of-life since 2020 https://en.wikipedia.org/wiki/OpenBSD#Releases

README.md

@@ -396,7 +396,6 @@ Simple deployment of [E-mail](https://en.wikipedia.org/wiki/Email) servers, e.g.
 - [docker-mailserver](https://docker-mailserver.github.io/docker-mailserver/edge/) - Production-ready fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.) running inside a container. Only configuration files, no SQL database. ([Source Code](https://github.com/docker-mailserver/docker-mailserver)) `MIT` `Docker`
 - [Dovel](https://dovel.email) - SMTP server that sends and receives emails according to a simple configuration file, with an optional web interface that you can use to browse your emails. ([Source Code](https://blmayer.dev/x/dovel)) `LGPL-3.0` `Go`
 - [emailwiz](https://github.com/LukeSmithxyz/emailwiz) - Luke Smith's bash script to completely automate the setup of a Postfix/Dovecot/SpamAssassin/OpenDKIM server on debian. `GPL-3.0` `Bash`
-- [Excision Mail](https://github.com/Excision-Mail/Excision-Mail) - Fullstack, security focused mailserver based on OpenSMTPD for OpenBSD using ansible. `ISC` `Shell/Ansible`
 - [homebox](https://github.com/progmaticltd/homebox) - Suite of Ansible scripts to deploy a fully functional mail server on Debian. Unobtrusive and automatic as much as possible, focusing on stability and security. `GPL-3.0` `Shell`
 - [Inboxen](https://inboxen.org) - Inboxen is a service that provides you with an infinite number of unique inboxes. ([Source Code](https://github.com/Inboxen/Inboxen)) `GPL-3.0` `Python`
 - [iRedMail](https://www.iredmail.org/) - Full-featured mail server solution based on Postfix and Dovecot. ([Source Code](https://github.com/iredmail/iRedMail)) `GPL-3.0` `Shell`