download_and_compile.sh: add missing Qt deps and remove redundant CMake setting
download_and_compile.sh: remove old dependencies
download_and_compile.sh: switch from Qt 5 to Qt 6 (optional dependency)
WindowsMouseCursor: remove old disabled code that causes lupdate warnings
WindowsMouseCursor: remove old disabled code that causes lupdate warnings
CI: use the C.UTF-8 locale
CI: use the C.UTF-8 locale
widgets.rst: fix directive name: 'Automethod' -> 'automethod'