Bug#1057359: qmake: use qmake6 when QT_SELECT=qt6

On Monday, December 11, 2023 5:26:14 PM CET Lisandro Damián Nicanor Pérez 
Meyer wrote:

> > +1 from me. qtchooser is no longer supported for Qt >= 6, so going
> > this way is just awesome.
> 
> Also worth to mention: this is something I should have done myself,
> but I currently lack the needed time, so Helmut took over. Many thanks
> to Helmut for this.

Agreed. Both to approach and to thanks to Helmut

/Sune

-- 
I didn’t stop pretending when I became an adult, it’s just that when I was a 
kid I was pretending that I fit into the rules and structures of this world. 
And now that I’m an adult, I pretend that those rules and structures exist.
   - zefrank