chore(deps): update dependency postcss-simple-vars to v7

Author: renovate[bot]

package-lock.json

@@ -50,7 +50,7 @@
     "css-loader": "5.2.7",
     "postcss-import": "^12.0.0",
     "postcss-loader": "4.3.0",
-    "postcss-simple-vars": "^5.0.1",
+    "postcss-simple-vars": "^5.0.1 || ^7.0.0",
     "style-loader": "4.0.0",
     "ts-loader": "^9.5.1",
     "url-loader": "4.1.1",