Update dependency prettier to v2.8.7

Author: renovate[bot]

extensions/jupyterlab/package.json

@@ -36,7 +36,7 @@
     "@jupyterlab/console": "^2.0.0 || ^3.0.0"
   },
   "devDependencies": {
-    "prettier": "2.0.5",
+    "prettier": "2.8.7",
     "rimraf": "3.0.2",
     "typescript": "3.9.3"
   },

jupyter_dash/labextension/package.json

@@ -36,7 +36,7 @@
     "@jupyterlab/console": "^2.0.0 || ^3.0.0"
   },
   "devDependencies": {
-    "prettier": "2.0.5",
+    "prettier": "2.8.7",
     "rimraf": "3.0.2",
     "typescript": "3.9.3"
   },