Upgrade to NodeJS 22 (LTS)

There are a few references to NodeJS 18, which is no longer maintained (5/2025)

For example: https://github.com/restatedev/restate/blob/132037488294ed43b80385fd550dbc30a245185c/.github/workflows/npm.yml#L52

NodeJS 22 is the Active LTS release until 11/2025

See https://github.com/restatedev/sdk-typescript/issues/526