meson: don't use Python module for host Python (#41959)

meson: don't use Python module for host Python (#41959)

Checking for pefile required that module to be made available for the
Python used to build systemd, even though it's only used at runtime,
potentially via a different Python installation.

Furthermore, Meson's Python module doesn't do the right thing when cross
compiling and looking up a Python for the host system, so this would end
up uselessly checking whether the build Python had the pefile module,
which is not needed. Even if it were made to check the host Python using
find_program, it still relies on being able to run its Python, which in
a cross scenario it probably wouldn't be able to do.

All in all, this check does more harm than good, and prevents building
ukify in valid configurations, so remove it.