[LyX/master] Cmake build: Start demanding at least version 5.1 if compiling with gcc

[Pavel Sanda]

On Mon, Nov 04, 2024 at 06:29:12PM +0100, Jean-Marc Lasgouttes wrote:
> Le 25/10/2024 ?? 08:23, Pavel Sanda a écrit :
> > Googling around
> > 16.04 has Qt 5.5.1 & Python 3.5 & gcc 5.4 available even if not default.
> > 18.04 has Qt 5.9.5 & Python 3.6 & gcc 7.5 available
> > 
> > We did unnecessarily drastic cut.
> > We can require gcc 7 only, but I think you just killed support Qt 5.9.5 anyway?
> 
> With my latest commits, we now support Ubuntu 18.04, which actually has
> python 3.8 in its repositories.
> 
> Everything compiles fine with gcc 7 and Qt 5.9.5.
> 
> Are we happy now?

I think this was good move. Pavel