Optimize 'gitlab-update' section in Timings output

Overview

Looking at the latest 'Timings' section from a recent gdk update:

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Timings
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platform-update: 99 sec(s)
preflight-checks: 15 sec(s)
preflight-update-checks: 0 sec(s)
gitaly-update: 48 sec(s)
gitaly-git-pull: 3 sec(s)
gitlab-shell-update: 18 sec(s)
gitlab-shell-git-pull: 3 sec(s)
gitlab-update: 243 sec(s)
gitlab-git-pull: 30 sec(s)
gitlab-metrics-exporter-update: 7 sec(s)
gitlab-workhorse-update: 47 sec(s)
jaeger-update: 0 sec(s)
object-storage-update: 0 sec(s)

Took 486 sec(s) total.

gitlab-update takes ~243 sec(s) which is pretty long, we should look to optimize this as much as possible.

Impacted categories

The following categories relate to this issue:

• gdk-reliability - e.g. When a GDK action fails to complete.
• gdk-usability - e.g. Improvements or suggestions around how the GDK functions.
• gdk-performance - e.g. When a GDK action is slow or times out.

Proposal

Investigate the logic behind the gitlab-update section and optimize.