Bump @babel/polyfill from 7.4.0 to 7.4.3 in /js

Bumps [@babel/polyfill](https://github.com/babel/babel) from 7.4.0 to 7.4.3.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/master/CHANGELOG.md)
- [Commits](https://github.com/babel/babel/compare/v7.4.0...v7.4.3)

Signed-off-by: dependabot[bot] <support@dependabot.com>

js/package-lock.json

@@ -1024,9 +1024,9 @@
       }
     },
     "@babel/polyfill": {
-      "version": "7.4.0",
-      "resolved": "https://registry.npmjs.org/@babel/polyfill/-/polyfill-7.4.0.tgz",
-      "integrity": "sha512-bVsjsrtsDflIHp5I6caaAa2V25Kzn50HKPL6g3X0P0ni1ks+58cPB8Mz6AOKVuRPgaVdq/OwEUc/1vKqX+Mo4A==",
+      "version": "7.4.3",
+      "resolved": "https://registry.npmjs.org/@babel/polyfill/-/polyfill-7.4.3.tgz",
+      "integrity": "sha512-rkv8WIvJshA5Ev8iNMGgz5WZkRtgtiPexiT7w5qevGTuT7ZBfM3de9ox1y9JR5/OXb/sWGBbWlHNa7vQKqku3Q==",
       "dev": true,
       "requires": {
         "core-js": "^2.6.5",

js/package.json

@@ -28,7 +28,7 @@
   "devDependencies": {
     "@babel/core": "^7.4.0",
     "@babel/plugin-syntax-dynamic-import": "^7.2.0",
-    "@babel/polyfill": "^7.4.0",
+    "@babel/polyfill": "^7.4.3",
     "@babel/preset-env": "^7.4.3",
     "babel-loader": "^8.0.5",
     "css-loader": "^2.1.1",