chore(deps): migrate from node-sass to dart-sass

node-sass is deprecated and its native bindings fail to build on
recent Node versions. Replace with the maintained `sass` package and
bump sass-loader to v10 (last major supporting webpack 4).

package.json

@@ -57,8 +57,8 @@
     "@vue/cli-service": "^4.3.1",
     "@vue/test-utils": "^1.0.0-beta.33",
     "babel-core": "7.0.0-bridge.0",
-    "node-sass": "^4.13.1",
-    "sass-loader": "^8.0.2",
+    "sass": "^1.77.0",
+    "sass-loader": "^10.5.2",
     "ts-jest": "^25.3.1",
     "ts-node": "^8.8.2",
     "typescript": "^3.8.3",