Use elastic_delete_by_query in search_spec

What does this MR do and why?

Related to #427067 (closed) and #413976 (closed) and #250331 (closed)

Switch to using elastic_delete_by_query spec to speed things up and hopefully fix the failureflaky-test

Screenshots or screen recordings

local spec runtime before

Finished in 22 minutes 16 seconds (files took 14.66 seconds to load)
31 examples, 1 failure

Failed examples:

rspec './ee/spec/requests/api/search_spec.rb[1:2:1:2:1:1:1:8:1:1]' # API::Search GET /groups/:id/-/search with correct params when elasticsearch is enabled when elasticsearch_limit_indexing is on when the namespace is indexed behaves like elasticsearch enabled for notes scope behaves like pagination returns a different result for each page

Randomized with seed 31765

local spec runtime after

Finished in 11 minutes 24 seconds (files took 14.14 seconds to load)
191 examples, 0 failures

Randomized with seed 31765

How to set up and validate locally

Specs only change, I ran with a failed seed from a pipeline failure (it failed locally too and also took a long time to run)

Test with

bundle exec rspec --seed 31765 ee/spec/requests/api/search_spec.rb

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.