Fix gitlab-topology-service to use pinned version when cloning

What does this merge request do and why?

This MR fixes a bug where cloning gitlab-topology-service didn't use the pinned version from GITLAB_TOPOLOGY_SERVICE_VERSION. The update verify job updated the service to the pinned version, but fresh clones fetched the latest. This adds the missing support/component-git-update step like other components.

Related to #2901 (closed)

How to set up and validate locally

1. Run make gitlab-topology-service/.git
2. You should see:

✅️ Successfully fetched and checked out '1898a62e7a029d4dee9f9bb2ede208ff5bfbd9c7' for 'gitlab-topology-service/'

Impacted categories

The following categories relate to this merge request:

• 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.

Merge request checklist

• This MR references an issue describing the change.
• This change is backward compatible. If not, please include steps to communicate to our users.
• Tests added for new functionality. If not, please raise an issue to follow-up.
• Documentation added/updated, if needed.
• Announcement added, if change is notable.
• gdk doctor test added, if needed.