Resolve "Create a release from master" (!297)

* fix: review

* #139: fix: re-enable Docker ARM build

* #239: feat: release du runtime from `runtime/*` branches

* #239: fix: clippy

* #269: fix: remove workaround from !239

* #239: feat: release du runtime from master

* #239: fix: create_client_release must not depend on runtime milestone

* #239: refact: rename `release_runtime` module to `gitlab`