Node v20 Tests

[MarkAckert]

Adds node v20 to backend systems and creates new tests for Node v20. Adds Node v20 to the nightly/release test suite.

Node 20 passing test:
https://github.com/zowe/zowe-install-packaging/actions/runs/9007882831/job/24748714570

[github-actions]

build 5218 SUCCEEDED.
Link to workflow run: https://github.com/zowe/zowe-install-packaging/actions/runs/9007501587

[github-actions]

Test workflow 4474 is started.
Running install test: Convenience Pax
The zowe artifact being used by this test workflow: libs-snapshot-local/org/zowe/2.16.0-PR-3826/zowe-2.16.0-pr-3826-5218-20240508193835.pax
Running on machine: zzow07
Result: SUCCESS
Link to workflow run: https://github.com/zowe/zowe-install-packaging/actions/runs/9007572408

[github-actions]

Test workflow 4475 is started.
Running install test: z/OS node v20
The zowe artifact being used by this test workflow: libs-snapshot-local/org/zowe/2.16.0-PR-3826/zowe-2.16.0-pr-3826-5218-20240508193835.pax
Running on machine: zzow06
Result: SUCCESS
Link to workflow run: https://github.com/zowe/zowe-install-packaging/actions/runs/9007882831

[1000TurquoisePogs]

I note in the log files that node 20 is used at runtime. Great!
But, also the logs have it so that node v16 is specified in the beginning, and then overridden to 20.

That's not an issue right now. But by september that should be switched to v18 default because v16 will be out of support in september I believe.