vendor: remove unused packages from vendor.json
vendor: remove unused packages from vendor.json

Signed-off-by: Simon Pasquier <38e2d22e48be18381a59028f88390cad04670376@redhat.com>

GoogleCloudPlatform/prometheus,prometheus/prometheus,keegancsmith/prometheus,kangwoo/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,kangwoo/prometheus,prometheus/prometheus,kangwoo/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,alileza/prometheus,prometheus/prometheus,kangwoo/prometheus,Gouthamve/prometheus,alileza/prometheus,prometheus/prometheus,keegancsmith/prometheus,Gouthamve/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,keegancsmith/prometheus,Gouthamve/prometheus,alileza/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus