Remove redundant script,style,link type attributes

[sirreal]

Attributes like type="text/javascript" on script tags and type="text/css" on style tags are redundant in HTML5. Remove them.

The script-loader and WP_Styles both make checks against current_theme_supports( 'html5', 'style' ) and current_theme_supports( 'html5', 'script' ), and multiple places in the rest of the codebase unconditionally produce type="text/css" and type="text/javascript" HTML attributes on the associated tags.

This is a legacy convention predating HTML5 in 2008 and can be removed. These are the default values when the attributes are absent, and this does not depend on or change with declared theme support.

Removing the type attribute simplifies logic and normalizes the produced HTML content.

This is part of #59883

See also PR#10641

Trac ticket: https://core.trac.wordpress.org/ticket/64428

Follow-up to r61411.

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[github-actions]

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