Upgrade node version minimum requirement

[charisk]

I believe we're expecting use of v15 and above so I've updated the engine definition.

Checklist

N/A:

• CHANGELOG.md has been updated to incorporate all user visible changes made by this pull request.
• Issues have been created for any UI or other user-facing changes made by this pull request.
• [Maintainers only] If this pull request makes user-facing changes that require documentation changes, open a corresponding docs pull request in the github/codeql repo and add the ready-for-doc-review label there.

[shati-patel]

Thanks, makes sense! 🚢

[edoardopirovano]

Should we not also be checking in an updated package-lock.json?

[aeisenberg]

It's a little strange that we have "@types/node": "^16.11.25" in dev dependencies, but the minimum node version is 15. Can we synchronize the two? And also, the package lock should be updated as @edoardopirovano mentions.

[aeisenberg]

We also need to make sure that we run the internal integration tests using the same version of node. This is something I can take care of.