Update dependency sass-loader to v7.3.1

Author: renovate-bot

package.json

@@ -100,7 +100,7 @@
     "optimize-css-assets-webpack-plugin": "5.0.3",
     "prettier": "1.18.2",
     "pretty-quick": "1.11.1",
-    "sass-loader": "7.1.0",
+    "sass-loader": "7.3.1",
     "script-ext-html-webpack-plugin": "2.1.4",
     "style-loader": "0.23.1",
     "terser-webpack-plugin": "1.4.1",