Add archived field in the wikis index

What does this MR do and why?

This MR will add a boolean field archived in the wikis index mapping. This field can be used to hide archived projects' wikis from the search result.

Screenshots or screen recordings

How to set up and validate locally

1. Open the rails console

bundle exec rails c

2. Run the following commands

require_relative 'ee/elastic/migrate/20230719211400_add_archived_to_wikis.rb' 
AddArchivedToWikis.new(20230719211400).migrate

3. Check the mapping of the commits index

curl -H 'Content-type: application/json' -XGET 'http://localhost:9200/gitlab-development-wikis/_mappings' | json_pp

4. Make sure there is a field archived with type as boolean is present

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 #416248 (closed)