chore(deps): update dependency prettier to ^2.8.7

Author: renovate[bot]

package.json

@@ -6,7 +6,7 @@
     "@sourcegraph/tsconfig": "^4.0.1",
     "eslint": "^7.18.0",
     "husky": "^4.3.8",
-    "prettier": "^2.2.1",
+    "prettier": "^2.8.7",
     "typescript": "^4.1.3"
   }
 }