Add index for faster search build name

What does this MR do and why?

Add index for faster search build name

This index will replace the existing one and allow more performant searches

This MR is split off from !166292 as the new application code will use this index that'll take quite a while to run

Database Optimization Queries

See: !166292

References

Please include cross links to any resources that are relevant to this MR This will give reviewers and future readers helpful context to give an efficient review of the changes introduced.

• https://docs.gitlab.com/ee/development/database/adding_database_indexes.html

MR acceptance checklist

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Screenshots or screen recordings

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Before	After

How to set up and validate locally

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Related to #463875