ci: Don't install libsoup-devel when building soup3 variant
This also disables trying to build the dmap plugin, and only installs libgdata-devel and libdmapsharing-devel in the libsoup2 variant.
CC: @ebassi
This also disables trying to build the dmap plugin, and only installs libgdata-devel and libdmapsharing-devel in the libsoup2 variant.
CC: @ebassi