babel: enable shippedProposals and use for toolkit as well

rollup.config.js

@@ -310,6 +310,7 @@ Dependencies:
         useBabel && babel({
           include: [
               'src/**',
+              'vendor/**',
               'node_modules/pdfjs-dist/**', // uses Promise.allSettled
           ],
           babelHelpers: 'runtime',
@@ -317,6 +318,7 @@ Dependencies:
           presets: [[
             '@babel/preset-env', {
               loose: true,
+              shippedProposals: true,
               bugfixes: true,
               targets: {
                 esmodules: true