Fix the CVE in sample library dependency.

[vaikas]

Expected Behavior

Examples rely on libraries / depedencies with non vulnerable deps.

Actual Behavior

https://github.com/knative/docs/security/dependabot/docs/serving/samples/cloudevents/cloudevents-nodejs/package-lock.json/axios/open

One of the examples was flagged as having a CVE.

Steps to Reproduce the Problem

Additional Info

Additional context
Add any other context about the problem here.

Install information:

• Platform (GKE, IKS, AKS, etc.):
• Knative Version: