Faster elasticsearch specs

What does this MR do and why?

Describe in detail what your merge request does and why.

Drastically reduces the overhead on :elastic tagged specs. This causes issues with some specs, so I've maintained the old setup as :elastic_clean and applied that manually to the failing specs.

Examples

Running ee/spec/controllers/ee/search_controller_spec.rb

Before

Finished in 39 minutes 13 seconds (files took 8.32 seconds to load)
71 examples, 0 failures

After

Finished in 1 minute 7.04 seconds (files took 9 seconds to load)
71 examples, 0 failures

Screenshots or screen recordings

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How to set up and validate locally

1. Enable elastic search by following https://gitlab.com/gitlab-org/gitlab-development-kit/blob/main/doc/howto/elasticsearch.md#enable-elasticsearch-in-the-gdk
2. gdk restart
3. Run the specs.

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.