[Feature] Eliminate W3 Validation Warnings for Script and Style type Attributes

[jessecowens]

Is your feature request related to a problem? Please describe. The HTML5 validator tool at https://validator.w3.org/nu/ throws warnings for including a type attribute for scripts and styles, eg: Warning: The type attribute is unnecessary for JavaScript resources. Warning: The type attribute is unnecessary for CSS resources.

Describe the solution you'd like Since WordPress 5.3, a theme_supports option has been included to pass these validation warnings: add_theme_support( 'html5', [ 'script', 'style' ] );

Additional context This issue was reported on the WordPress.org forums.