[wip][patch] use qmake with autoconf for qt5 too

[José Matos]

On Mon, 2024-06-17 at 17:25 +0200, Jean-Marc Lasgouttes wrote:
> I pushed this change to master, along with a warning when the qmake
> way did not work. Please tell me when this triggers a warning, so
> that we can understand what happens and how to solve it.
> 
> JMarc

Running this on Fedora 40. FWIW I am on KDE (Wayland).

The configure stage works, without a warning, but then at the end of
the build stage I get:

  CXXLD    lyx
/usr/bin/ld: frontends/qt/liblyxqt.a(GuiApplication.o): undefined
reference to symbol 'xcb_send_event'
/usr/bin/ld: /usr/lib64/libxcb.so.1: error adding symbols: DSO missing
from command line

-- 
José Abílio