Support for NodeJS v18.12.0 LTS
Upgrading to NodeJS v18.12.0, now that has become the active LTS version.  Works on my mac and Raspberry Pi, but on Synology I get:
```
homebridge@ds2:/volume1/homebridge $ hb-service update-node
ℹ Updating Node.js from v16.17.1 to v18.12.0...
✖ Cannot update Node.js on your system. Synology DSM 7 does not currently support Node.js 18 or later.
```

Is this is limitation of the Homerbidge package or of NodeJS/Synology themselves?  Anything I can do?