audio/drumgizmo: Disable ARM build, update maintainer address

While here, pet portfmt.

PR: 297353
Reported by: https://portsfallout.com/fallout?port=audio%2Fdrumgizmo%24
Approved by: osa, vvd (Mentors, implicit)
MFH: 2026Q3

(cherry picked from commit 0d645caea55b76c9ddf1aa574ce96dd562ba0cb4)