Upgrade Node.js to the latest stable release

[stvnrlly]

We need to upgrade our Node.js version in the admin project to the latest stable release. This may require a bit of extra project configuration and it should also prepare us to update our JavaScript packages as well, but the package updates should be handled separately.

Implementation Sketch and Acceptance Criteria

• Update our project's use of nvm to the latest version
• Using nvm, update the project to the latest stable release of Node.js
• Ensure that npm is also updated as part of this (it often gets updated beyond what's in the latest Node.js release)
• Modify any project configuration (environment variables, application configuration, etc.) that requires updating to support the new release
• Update the admin project's README to reflect any changes in set up and version numbers

Security Considerations

• We need to make sure we're running supported versions of Node.js; even though it's not used to run any application code, it is used to manage our JavaScript packages and static assets.
• Updating Node.js helps our project stay secure with the latest updates and patches that address security vulnerabilities and stability issues.