Stop using DAQmx-based simulated device in nifgen system tests

[sbethur]

• [x] This contribution adheres to CONTRIBUTING.md.

~- [ ] I've updated CHANGELOG.md if applicable.~

~- [ ] I've added tests applicable for this pull request~

What does this Pull Request accomplish?

Stop using DAQmx-based simulated device in nifgen system tests, now that the internal issues 227842 and 999932 are fixed.

List issues fixed by this Pull Request below, if any.

• Fix #1375
• Fix #1376

What testing has been done?

System tests will run as part of PR pipeline.

[sbethur]

test this please

[sbethur]

test this please

[sbethur]

test this please

[sbethur]

This is blocked until NI-FGEN driver runtime is updated to beyond 20.0 on nimi-bot.

[sbethur]

/AzurePipelines run

[ni-jfitzger]

Thanks for your work on this @sbethur. I'm reimplementing it against master and fixing any remaining issues in #2010, so I'm closing this.