Bump autoprefixer from 9.6.1 to 9.7.3 (#12519)

Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 9.6.1 to 9.7.3.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/master/CHANGELOG.md)
- [Commits](https://github.com/postcss/autoprefixer/compare/9.6.1...9.7.3)

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

package.json

@@ -70,7 +70,7 @@
     "@clusterws/cws": "^0.16.0",
     "array-includes": "^3.0.3",
     "arrow-key-navigation": "^1.1.0",
-    "autoprefixer": "^9.6.1",
+    "autoprefixer": "^9.7.3",
     "axios": "^0.19.0",
     "babel-loader": "^8.0.6",
     "babel-plugin-lodash": "^3.3.4",