Fix global styles duotone not rendering in post editor

[ajlende]

Global styles duotone filters were not rendering in the post editor (there is a separate issue for the site editor (WordPress/gutenberg#37727). This fixes that by adding wp_global_styles_render_svg_filters to the in_admin_header so it renders in the body before the editor.

To test, use a theme which adds duotone filters to a block in theme.json (Skatepark is one such example). Or add the following to twentytwentytwo's theme.json and ensure that an image added to a post is shown with the duotone filter by default in both the editor and front end.

{
    "styles": {
        "blocks": {
            "core/image": {
                "filter": {
                    "duotone": "var(--wp--preset--duotone--primary-and-secondary)"
                }
            }
        }
    }
}

Trac ticket: https://core.trac.wordpress.org/ticket/55190

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This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

[hellofromtonya]

LGTM 👍 Marking for commit. Thank you @ajlende ⭐

[hellofromtonya]

Committed via https://core.trac.wordpress.org/changeset/52768.