github: fetch git tags before testing

github: fetch git tags before testing

GitHub workflows fetch a clone of the dracut repository which doesn't
contain git tags, thus "breaking" the RPM build in certain situations
i.e.:
DRACUT_MAIN_VERSION in Makefile is defined as an output of `git describe`,
which in full git clone returns a tag with a numeric version. However,
without tags it returns SHA of the last commit, which later propagates into
`Provides:` attribute of the built RPM and can break dependency tree when
installed