Merge branch 'andrey-gdk-build-improvements' into '16-3-stable-ee'

Remove gdk base image and pin gdk sha

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/131121



Merged-by: Dan Davison <ddavison@gitlab.com>
Approved-by: Nao Hashizume <nhashizume@gitlab.com>
Approved-by: Dan Davison <ddavison@gitlab.com>
Co-authored-by: Andrejs Cunskis <acunskis@gitlab.com>