This now requires `--host` and `--with-build-python` to be passed to the
configure script when cross compiling; the former we simply do like in
many other package.sh scripts as well, the latter we point to `python3`,
which is expected to match the port's version anyway.
Add two patches to allow Python's package manager to work on Serenity:
- The first one enables zlib module, which is needed for `ensurepip`
command;
- The second patch fixes pip downloads, so it's possible to install
packages from the PyPI repository.
