chore(deps): update dependency prettier to v2.8.7

Author: renovate[bot]

package.json

@@ -62,7 +62,7 @@
     "eslint": "7.24.0",
     "eslint-config-prettier": "6.15.0",
     "jest": "26.6.3",
-    "prettier": "2.2.1",
+    "prettier": "2.8.7",
     "rxjs-marbles": "^6.0.1",
     "supertest": "^4.0.2",
     "ts-jest": "26.4.0",