configure: allow PyPI access for python 'tooling' dependencies

We actually do not allow our meson requirements to be fetched online
because we strictly prefer the vendored version. Move the tooling group
installation to a different invocation that does allow PyPI to be
accessed when configure is run without explicitly disabling PyPI access.

This will allow QEMU to download and install python3-wheel for you if
you don't have it in your host environment.

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Message-id: 20260225191255.955585-1-jsnow@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>