chore(deps): update dependency gaxios to v4 (#524)

Co-authored-by: Nicole Zhu <69952136+nicoleczhu@users.noreply.github.com>
Co-authored-by: Justin Beckwith <justin.beckwith@gmail.com>

Author: 3 people

samples/package.json

@@ -20,7 +20,7 @@
   },
   "devDependencies": {
     "chai": "^4.2.0",
-    "gaxios": "^3.0.0",
+    "gaxios": "^4.0.0",
     "mocha": "^8.0.0"
   }
 }