Quoted RFC has been superseded, information obsolete

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Which topic?

https://developer.adobe.com/commerce/php/development/cache/page/public-content/

### What's wrong with the content?

In the Public Content page, Invalidate public content Section, the article is referring to the RFC-2616 section 13, the RFC-2616 has been superseded and there are newer version RFC 7234 and RFC 9110 about caching specifically.

### What changes do you propose?

Use newer version RFC, RFC 7234 and RFC 9110. Refer to this link https://www.rfc-editor.org/rfc/rfc9110.html

### Anything else that can help to cover this?

_No response_

Open the Public Content page at the linked Adobe Commerce URL and go to the Invalidate public content section. Replace the RFC-2616 reference with the newer RFC references named in the issue, including RFC 9110. The work is done when the section no longer cites the superseded RFC.

Written by the indexing model from the issue text.