ui.rc files: consistenly use <gui> instead of deprecated <kpartgui>

2 jobs for master in 34 minutes and 25 seconds (queued for 42 minutes and 55 seconds)
Status Job ID Name Coverage
  Build
passed #80656
build_clazy_clang_tidy

00:24:05

passed #80655
linux kf5-qt5 qt5.15

00:10:19

6.0%