Update dependency prettier to v2.8.8

Author: renovate[bot]

package.json

@@ -71,7 +71,7 @@
     "eslint-plugin-qunit": "7.3.4",
     "loader.js": "4.7.0",
     "npm-run-all": "4.1.5",
-    "prettier": "2.7.1",
+    "prettier": "2.8.8",
     "qunit": "2.19.4",
     "qunit-dom": "2.0.0",
     "release-it": "14.14.3",