FindPython: Add cross-compilation support for Debian-based systems.

Debian-based Linux distributions locate their architecture-specific
pythonX.Y-config tool at /usr/bin/<arch>-python<X.Y>-config.

We first attempt to find and use the architecture-specific
pythonX.Y-config tool. If the pythonX.Y-config tools are absent, then we
proceed to find the architecture-specific Python libraries.

Fixes: #17912
1 file changed