Use shared Browserslist config for Babel in "vue/"

Instead of hardcoding the target browsers now they are got from the
"browserslist-config-nextcloud" package; at this point it makes no
difference, as the same versions as the hardcoded ones are used in the
package, but this will make possible to automatically keep the target
browsers in sync with those used in the Nextcloud server.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>