x11/roxterm: Update to 3.18.2

• Switch to DISTVERSION
• Cleanup dependencies
• Pet portclippy and portfmt
• Take maintainership

ChangeLog: https://github.com/realh/roxterm/releases/tag/3.18.2

		https://github.com/realh/roxterm/releases/tag/3.18.1

MFH: 2026Q3
(cherry picked from commit 660051e4aff8d49d0117ff88a8cb84bd65c6a088)