sysutils/conky: update to 1.21.4

ChangeLog: https://github.com/brndnmtthws/conky/releases/tag/v1.21.4

Features

• Add Ubuntu 24.04 to CI & release assets

Bug fixes

• Fix AC/battery detection logic on FreeBSD.
• Fix minimum_height not scaled with dpi_scale like minimum_width

Miscellaneous

• Bump version
• Drop macos 11 build

Dependencies

• build(deps): bump braces and readdirp in /web
• Bump web deps
• Apply npm audit fix.
• Bump web deps