Delete usages for metrics dashboard in models

What does this MR do and why?

Remove the relationship between the Environment model and Annotations.

Fix the specs for this change. Delete Annotations create and delete service.

The files that are partially updated will be eventually removed in subsequent MRs for removals.

Screenshots or screen recordings

NA

How to set up and validate locally

1. Delete mutation now raises resource not available error.
2. Model relationship between ENV and Annotations is not used anywhere else.
3. Pipeline should be 🍏

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #397139 (closed)