5pkgs.gomuks: build TUI client from new codebase with goolm encryption
Use the gomuks v0.2601.0 codebase (cmd/gomuks-terminal) instead of the
abandoned v0.3.1 TUI. This version uses mautrix with built-in goolm,
a pure-Go olm replacement, avoiding the insecure and deprecated libolm
C library entirely. E2EE works without CGO.