games/automuteus: Update 8.3.6 => 8.3.7, take maintainership

Changelog:
https://github.com/automuteus/automuteus/releases/tag/8.3.7
(It consists of purely non-functional changes - just a GitHub workflow
update).

• Upstream rename GH_ACCOUNT to PORTNAME.
• "Parametrize" automuteus with ${PORTNAME}.
• Replace 2 MKDIRs with single.
• Replace CP with INSTALL_DATA.

PR: 289193
Co-authored-by: Vladimir Druzenko <vvd@FreeBSD.org>