Remove init_tools.sh from workspace-tools

What does this MR do and why?

Removes init_tools.sh script from this project because it has already been moved into the rails repo with this MR: Move init_tools script into gitlab rails (gitlab-org/gitlab!191251 - merged)

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.