[DOCS] Update 'Scalability' links after page title change

[kosabogi]

Overview

This is a follow up PR for this change.

After the page title change from Scalability to Getting ready for production, we need to review and update all instances of <<scalability, some Link text>> across the Elasticsearch guide. This ensures that the link texts make sense and correctly reflect the updated title.

Steps:

• Search for all occurrences of <<scalability, some Link text>> across the guide.
• Review each instance and update the link text to match the new page title and context appropriately.

[kosabogi]

Checked the following guides:

• Elasticsearch guide
• Elasticsearch Service docs
• Kibana docs
• Starting with the Elasticsearch Platform and its Solutions

Didn't find any links related to the Get ready for production page.