Draft: gitlab-ci: build docker image as part of the CI

This makes Gitlab CI docker image update part of the CI run and thus in sync with Dockerfile in repository.

changed milestone to %Turris OS 6.0

requested review from @jschlehofer

assigned to @jschlehofer

added 120 commits

• ed098802...a419e81d - 118 commits from branch hbl
• 3ce6cf37 - gitlab-ci: build docker image as part of the CI
• 739c80c8 - gitlab-ci: add missing updater-ng dependency

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assigned to @mvasilek and unassigned @jschlehofer

requested review from @mvasilek and removed review request for @jschlehofer

added High label

approved this merge request

assigned to @jschlehofer and unassigned @mvasilek

added 222 commits

• 739c80c8...2cf3b4f1 - 220 commits from branch hbl
• e6096a18 - gitlab-ci: build docker image as part of the CI
• 29921f25 - gitlab-ci: add missing updater-ng dependency

Compare with previous version

merged