Add runner for Node 20 LTS

[ncook-hxgn]

Please check our current Issues to see if someone already reported this https://github.com/Microsoft/azure-pipelines-task-lib/issues

Environment

azure-pipelines-task-lib version: 4.3.1

Issue Description

Please provide a node20 task runner

Expected behaviour

I'd like a node20 task runner to run node 20 code.

Actual behaviour

There are runners node, node10, and node16, representing LTS releases of NodeJS.

Logs

Don't get me wrong, my code works fine. I may be misunderstanding, but I'd just like to see a node runner for each nodelts release.

[gitnubster]

I would like to see this also. As far the tasks.schema.json concerns, the execution handler Node20_1 does not exist. (While it does at agent side.)
In a task I have:

"$schema": "https://raw.githubusercontent.com/Microsoft/azure-pipelines-task-lib/master/tasks.schema.json",
"execution": {
    "Node20_1": {
      "target": "$(currentDirectory)/taskfile.js",
      "argumentFormat": "",
      "workingDirectory": "$(currentDirectory)"
    }
  }

And VSCode shows:
Property Node20_1 is not allowed.

[Herve-M]

For the curious one:
Runner updates for Node20:

• Support Node 20 handler azure-pipelines-agent#4346
• Replace node20 handler with node20_1 azure-pipelines-agent#4518

task-lib update for Node20:

• Add node 20 support to task-lib for testing and pick highest node version for tests #1039
• Migrate to Node 20 #962

It seems that Node20_1 is usable as this task use it already: https://github.com/microsoft/azure-pipelines-tasks/blob/master/Tasks/NotationV0/task.json

[Herve-M]

According to this Azure DevOps changelog it has been released even if the diff. PR are still open..

See how-to notes.

[ncook-hxgn]

Docs look good, can't wait to use the node20 runner :)