Synchronize node version between CI & local

[pepopowitz]

This is followup work to #976.

In that PR we introduced a .nvmrc file to specify node versions for local environments. It does not currently match the exact specified version for CI, though (16.15.1 vs 16). We should synchronize these versions.

Included in this work

• Configure any actions that are hardcoding the node version number to get the node version from the .nvmrc file. This change is described and demonstrated in actions/setup-node#338.
• Decide whether we want to specify only the major version (16), or the fully qualified version (16.15.1). The tradeoffs:
  • Specifying the major version gives us free node patch/minor version updates on CI, but it doesn't guarantee that local and CI would use the same fully qualified version.
  • Specifying the fully qualified version guarantees that local and CI are using the same version, but to get node version updates we have to manually update the nvmrc.