[Themes] Update theme support documentation for HTML5 script

Issue Description

Ticket 64442 and changeset 61415 are removing and deprecating the HTML5 script theme support option. More details are in the ticket.

Some documentation pages mention HTML5 script theme support and seem to be a mix of generated and human-written documentation. These pages should be updated to remove references to HTML5 script theme suppport.

A changelog can mention that WordPress 7.0 deprecated HTML5 script theme support.

URL of the Page with the Issue

• https://developer.wordpress.org/reference%2Ffunctions%2Fadd_theme_support%2F/#html5
• https://codex.wordpress.org/Theme_Markup#Adding_Theme_Support

Section of Page with the issue

https://developer.wordpress.org/reference%2Ffunctions%2Fadd_theme_support%2F/#html5 - the HTML5 section.

https://codex.wordpress.org/Theme_Markup - "Adding Theme Support" uses script in its example.

Why is this a problem?

Themes should not check HTML5 script support and with WordPress 7.0 they can stop adding HTML5 script support, it should have no impact.

Suggested Fix

Update to remove references to HTML5 script support.

Props @dmsnell for spotting this.