fix(deps): update dependency is-plain-obj to v4

Author: renovate-bot

package-lock.json

@@ -34,7 +34,7 @@
   "license": "MIT",
   "dependencies": {
     "filter-obj": "^2.0.2",
-    "is-plain-obj": "^3.0.0",
+    "is-plain-obj": "^4.0.0",
     "path-exists": "^4.0.0",
     "toml": "^3.0.0"
   },