Merge pull request #1063 from plotly/renovate/css-loader-4.x

Update dependency css-loader to v4

Author: dmt0

package.json

@@ -67,7 +67,7 @@
     "babel-jest": "26.3.0",
     "babel-loader": "8.1.0",
     "babel-plugin-module-resolver": "4.0.0",
-    "css-loader": "3.6.0",
+    "css-loader": "4.3.0",
     "cssnano": "4.1.10",
     "enzyme": "3.11.0",
     "enzyme-adapter-react-16": "1.15.4",