chore(docs): Remove cache warming documentation

[atticoos]

SUMMARY

The cache warming strategies perform unauthorized GET requests that are redirected to the login page.

As a result, they do not work as documented. This removes documentation references until these are ready for production use.

ADDITIONAL INFORMATION

• Has associated issue: Cache warm-ups never succeed #9597, warm up cache does not work #18933
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[eschutho]

Thanks for the documentation change @ajwhite. I think someone is working on fixing this feature, but it looks safe to remove the documentation now to minimize confusion.