Support Node 20

[itpropro]

Node 20 is the current LTS version of Node and should be supported. This impacts

• App Service
• Azure Functions
• Static Web Apps

Node 18 is only receiving security updates at this point and Node 16 is completely EOL and should therefor be removed as supported version.

[ejizba]

Hi @itpropro, I only work on Azure Functions, but we already support Node 20 in preview and you can see the latest estimates for GA on our roadmap here: https://github.com/Azure/azure-functions-nodejs-library/wiki/Roadmap

Closing as duplicate of Azure/azure-functions-nodejs-library#170