Modernize jest-junit CI and local dev setup

[palmerj3]

Removes libxmljs and replaces with libxml2-wasm.

Also upgrades jest to 30.0.0-alpha.3 to make use of async setupFilesAfterEnv.

[palmerj3]

@SimenB can you take a look and approve & merge if you agree?

I found a new xml parser & validator that will validate all unit tests against the junit xsd. Same behavior we've had the entire project.

I needed to force unit tests to run under Jest 30 and utilize node experimental-vm-modules. As such, I removed integration tests for testResultsProcessor since that's no longer a thing in Jest 30.

This change will fix CI for all current and future PRs.