fix(deps): update dependency lowercase-keys to v3

Author: renovate[bot]

package-lock.json

@@ -17,7 +17,7 @@
     "@probot/get-private-key": "^1.1.0",
     "@types/aws-lambda": "^8.10.85",
     "probot": "^12.1.1",
-    "lowercase-keys": "^2.0.0"
+    "lowercase-keys": "^3.0.0"
   },
   "devDependencies": {
     "@types/jest": "^27.0.2",