function packUiIIFEmin(cb) {
    src(`${feModuleSrc}/ui.js`)
        .pipe(gulpEsbuild({
            outfile: 'ui.iife.min.js',
            bundle: true,
            format: 'iife',
            platform: 'browser',
            minify: true,
            sourcemap: true,
            target: [
                // 'es2019',
                // Start of 2019
                'chrome72',
                'safari12.1',
                'firefox65',
                'opera58',

                // For private class fields:
                // 'chrome74',   // Apr 23, 2019
                // 'opera62',    // Jun 27, 2019
                // 'edge79',     // Jan 15, 2020
                // 'safari14.1', // Apr 26, 2021
                // 'firefox90',  // Jul 13, 2021

                // If we need top-level await
                // 'chrome89',  // March 1, 2021
                // 'edge89',
                // 'opera75',   // Mar 24, 2021
                // 'firefox89', // Jun 1, 2021
                // 'safari15',  // Sep 20, 2021
            ],
        }))
        .on('error', function(err) {
            console.error('[packUiIIFEmin] ERROR ', err)
            cb(err)
        })
        .pipe(greplace(/="(.*)-src"/, '="$1-iife.min"'))
        .pipe(dest(feDest))
        .on('end', function() {
            // in case of success
            cb()
        })
}
ESBuild ui.js as IIFE minified
@param {Function} cb Callback