Exclude Categories from RSS Feed

<?php
// Add the numeric category IDs you want to exclude from the RSS feed.
add_filter( 'request', 'scseed_exclude_categories_from_rss' );
if ( ! function_exists( 'scseed_exclude_categories_from_rss' ) ) {
    function scseed_exclude_categories_from_rss( $qv ) {
        if ( ! isset( $qv['feed'] ) ) {
            return $qv;
        }
        // Replace with the IDs of the categories to exclude.
        $exclude_ids = apply_filters( 'scseed_rss_excluded_cat_ids', [] );
        if ( ! empty( $exclude_ids ) ) {
            $qv['category__not_in'] = array_map( 'absint', (array) $exclude_ids );
        }
        return $qv;
    }
}