Docs: Update or remove broken reference to in Gitlab CLI docs

Problem to solve

This installation instructions for Gitlab CLI mentions an install.sh script that does not exist.

Proposal

Update or remove the link

Who can address the issue

None

Other links/references

Docs Page: https://gitlab.com/gitlab-org/cli/-/blob/main/docs/installation_options.md

Referenced URL: https://gitlab.com/gitlab-org/cli/-/raw/main/scripts/install.sh

I checked the repo quickly and I don't know that the script exists at all anymore?