Fix: (webpack.config.js) css-loader API change (#1508)

* Fix: (webpack.config.js) css-loader API change

The build was broken in
<https://github.com/pydata/pydata-sphinx-theme/commit/185a37aa36820f77bffa4c87a772092e9e7cc380>/<https://github.com/pydata/pydata-sphinx-theme/pull/1494>.

This change fixes the build, and it seems to be in accordance with the
current API as described at <https://github.com/webpack-contrib/css-loader/blob/c6f36cf91ac61743a70e81cfb077faa0f8730ebe/README.md#boolean>.

Closes <#1507>.

* dedup

* restore version bump

---------

Co-authored-by: Daniel McCloy <dan@mccloy.info>

package.json

@@ -7,7 +7,7 @@
   "devDependencies": {
     "axe-core": "^4.6.3",
     "copy-webpack-plugin": "^11.0.0",
-    "css-loader": "^3.4.2",
+    "css-loader": "^6.8.1",
     "css-minimizer-webpack-plugin": "^4.2.2",
     "dedent": "^0.7.0",
     "html-webpack-plugin": "^4.3.0",

webpack.config.js

@@ -159,7 +159,7 @@ module.exports = {
       test: /\.scss$/,
       use: [
         {loader: MiniCssExtractPlugin.loader},
-        {loader: "css-loader?-url"}, //url()-inlining turned off
+        {loader: "css-loader", options: { url: false }},
         {loader: "sass-loader",},
       ],
     }],