bindings: python: tests: provide and use system.check_kernel_version()

bindings: python: tests: provide and use system.check_kernel_version()

We claim that libgpiod python bindings have no dependencies other than
the python standard library but this is not true - the tests do depend
on deprecated distutils for kernel version parsing.

As distutils is deprecated, the recommended improvement is to use the
Version class from packaging.version but this would too entail pulling
in an external module.

Let's instead implement the kernel version check in C using uname() and
put it into the tests.system extension. This allows us to entirely drop
the distutils import.

Reviewed-by: Vincent Fazio <vfazio@xes-inc.com>
Link: https://lore.kernel.org/r/20241120-drop-distutils-v1-3-7498e8b3babe@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>