* Add certain variables to find Qt's dependencies to the CMake
toolchain file because these variables would otherwise needed to
be set every time Qt 6 is used
* Add a static variant
* Not fully tested yet
* Further repos besides base and svg will be added later
Initial motivation of adding the flag was better consistency with
compile flags used for regular Arch Linux packages.
However, adding -fstack-protector-strong seems to cause segmentation
faults even before main() is called.
The issue is not reproducible with a simple hello world app and also
not reproducible when launching the app under Linux with WINE. But
a full-blown Qt 5 app crashes in the way described.
Martchus