Makefile: change default target to include check_assets (#5932)
Makefile: change default target to include check_assets (#5932)

The CI has only to execute "make" to run all necessary checks.

Signed-off-by: Simon Pasquier <38e2d22e48be18381a59028f88390cad04670376@redhat.com>
alileza/prometheus,prometheus/prometheus,kangwoo/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,kangwoo/prometheus,prometheus/prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,prometheus/prometheus,keegancsmith/prometheus,alileza/prometheus,Gouthamve/prometheus,Gouthamve/prometheus,prometheus/prometheus,kangwoo/prometheus,keegancsmith/prometheus,Gouthamve/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,kangwoo/prometheus,alileza/prometheus,Gouthamve/prometheus,GoogleCloudPlatform/prometheus