Server: Upgrade NodeJS to v24

[personalizedrefrigerator]

Summary

Upgrades the server docker image from Node v18 to v24. Node 18 is EOL.

See also: #13700.

Testing

CI testing:

• Tests pass with Node v24 (see Chore: CI: Upgrade NodeJS to v24 #13700).
• The docker image is built in CI, with Node v24.

[personalizedrefrigerator]

Additional testing done locally:

1. It's possible to build and run the new docker image locally with Podman (locally replacing ${APP_PORT} with 22300 in Dockerfile.server).
   • Command: podman-compose -f ./docker-compose.server-dev.yml up.
2. If the sync fuzzer is modified to use the server instance started in (1), then the sync fuzzer runs successfully for >= 50 steps.