[Development] Proposal to raise the minimum CMake version needed to build and use Qt 6.9

[Sune Vuorela]

On 2024-12-02, Alexandru Croitor via Development <development at qt-project.org> wrote:
> Yocto 4.0 has it, debian 11 and 12 have it, ubuntu 22 and 24 have it, RHEL 8 and 9 have it, so I don't think this should be too controversial.

With my debian and user hat on, I don't think caring for debian old
stable (currently Debian 11) is needed, but it is always nice.

/Sune