ADD TO FUNCTIONS.PHP:
add_action('admin_head', 'my_custom_admin_css');
function my_custom_admin_css() {
echo '<style>
.notice.notice-error.jquery-migrate-dashboard-notice {
display: none;
}
li#wp-admin-bar-enable-jquery-migrate-helper {
display: none;
}
</style>';
}
ADD CSS TO FRONT OF SITE:
li#wp-admin-bar-enable-jquery-migrate-helper {display: none;}