* On a windows job-build, we don't need to install Fedora dependencies.
  This change makes only one dnf install be ran per job.

* On a meson build, we should build spice-protocol with meson too.

Moving this before_script rule to each job makes all of this clear.

So, this patch does change for fedora-meson, the build of
spice-protocol with meson and we don't (explicitly) install any of
$DEPS_FEDORA

v1 -> v2:
- Remove initial '_' from build folder filenames (Frediano);
- Always use '-' instead of '_' in build folder filenames (Frediano);

Signed-off-by: Victor Toso <victortoso@redhat.com>
Acked-by: Frediano Ziglio <fziglio@redhat.com>