Update external dependencies to current versions

Update all submodules to the current versions in the repositories.

The updated versions are added in preparation to changes in the respective packages:

• archlinux/packaging/packages/python-build!1 (merged)
• archlinux/packaging/packages/python-flit-core!1 (merged)
• archlinux/packaging/packages/python-installer!1 (merged)
• archlinux/packaging/packages/python-packaging!1 (merged)
• archlinux/packaging/packages/python-pyproject-hooks!1 (merged)
• archlinux/packaging/packages/python-setuptools!2 (merged)
• archlinux/packaging/packages/python-wheel!1 (merged)

The bootstrap workflow is documented in archlinux/packaging/packages/python!4