This code will remove the text near the breadcrumb title generated by rankmath plugin

code_for_rankmath.php

add_filter( 'rank_math/frontend/breadcrumb/items', function( $crumbs, $class ) {
    //Title is the firs key of the last sub array
    
    end($crumbs);              // move the internal pointer to the end of the array
    $last_key = key($crumbs);  // fetches the key of the element pointed to by the internal pointer

    //Here I don't use get_the_title because it run after filters are applied.
    //This causes that stars near title will appear in schema title
    $crumbs[$last_key][0] = get_post_field('post_title', get_the_ID(), 'raw');
    
    // And return the breadcrumbs
    return $crumbs;
}, 10, 2);