gh_actions: if draft is enabled also install draft packages

[sphaero]

See:

zproject/zproject_gh_actions.gsl

Lines 205 to 212 in 7fdba3a

	- name: Add debian packages
	if: matrix.os == 'ubuntu-20.04'
	uses: myci-actions/add-deb-repo@10
	with:
	repo-name: obs
	repo: deb http://download.opensuse.org/repositories/network:/messaging:/zeromq:/git-stable/xUbuntu_20.04/ ./
	keys-asc: https://download.opensuse.org/repositories/network:/messaging:/zeromq:/git-stable/xUbuntu_20.04/Release.key
	install: ${{ matrix.PACKAGES }}

It always installs from stable but for draft you might need draft support from other libs as well