Update dependency prettier to v2.8.7

Author: renovate[bot]

package-lock.json

@@ -34,6 +34,6 @@
     "@snowpack/plugin-webpack": "3.0.0",
     "@types/snowpack-env": "2.3.3",
     "dependency-cruiser": "10.0.4",
-    "prettier": "2.3.2"
+    "prettier": "2.8.7"
   }
 }