CI: Package macOS artifacts

This is needed so that the built contribs are actually packaged.

extras/ci/gitlab-ci.yml

@@ -163,7 +163,7 @@ macos:
             curl -f -L ${VLC_PREBUILT_CONTRIBS_URL} -o vlc-contrib-$TRIPLET-latest.tar.bz2
             cd ../../
         else
-            EXTRA_BUILD_FLAGS="-c"
+            EXTRA_BUILD_FLAGS="-c -p"
         fi
         mkdir build && cd build
         ../extras/package/macosx/build.sh $EXTRA_BUILD_FLAGS