PROF-5089: Align Rate Limiting Documentation and Configuration

[johncollinson2001]

Summary

Aligns rate limits across integration test and production environments and updates the OAS specification to correctly document these limits, ensuring consistency between configuration and documentation.

Changes

• Aligned rate limits in manifest_template.yml between int and prod environments
• Updated documentation in service-search-api.yaml to reflect accurate rate limits
• Removed environment-specific discrepancies to ensure consistent behavior across non-sandbox environments

Reviews Required

• Dev
• Test
• Tech Author
• Product Owner

Review Checklist

ℹ️ This section is to be filled in by the reviewer.

• I have reviewed the changes in this PR and they fill all or part of the acceptance criteria of the ticket, and the code is in a mergeable state.
• If there were infrastructure, operational, or build changes, I have made sure there is sufficient evidence that the changes will work.
• I have ensured the changelog has been updated by the submitter, if necessary.

[nigelatwell]

Happy to merge