* Use an older glibc so resulting binaries can run
on older systems (without having to link statically
against glibc)
* Call packages static-compat-* to make it clear that
these packages are intended for compatibility with
older distributions
* Add further libraries to get static-compat-qt6-base
and some other static-compat-qt6-* packages building
* 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
Martchus