Allow duotone support control within theme.json

[colorful-tones]

What problem does this address?

I noticed that my block theme outputs a series of <svg> elements in the footer of my theme, and then I realized that they're all coming from duotone. So, I thought maybe I can disable all duotone from theme.json with this:

{
	"version": 1,
	"settings": {
		"color": {
			"customDuotone": false,
			"duotone": []
                }
        }
}

However, all of the <svg> are still there. This is not ideal for performance. I would prefer to have the ability to not have all those superfluous <svg> output if I do not want/need them.

What is your proposed solution?

If the two keys exists in the theme.json then disable all duotone support and do not output <svg> with add_filter( 'render_block', 'gutenberg_render_duotone_support', 10, 2 );

I'm currently running WordPress 5.8.1 and Gutenberg plugin 11.7.1

[colorful-tones]

It seems that this will actually disable the <svg> from being output and was just a user error on my end:

{
	"version": 1,
	"settings": {
		"color": {
			"duotone": null
                }
        }
}