Reinstate macOS CI builds of Comet with Spark 4.0.0

[andygrove]

What is the problem the feature request solves?

In #1830 we disabled running PR builds for Spark 4.0.0 on macOS due to OOM. We need to fix this.

Describe the potential solution

No response

Additional context

No response

[andygrove]

@manuzhang builds are failing again with OOM errors now that these tests have been enabled:

See https://github.com/apache/datafusion-comet/actions/runs/20439562919/job/58729039027?pr=2956 for example.

*** RUN ABORTED *** (14 minutes, 52 seconds)
  java.lang.OutOfMemoryError: unable to create native thread: possibly out of memory or process/resource limits reached

[manuzhang]

@andygrove Not sure why my PR passed all tests while it fails now. Do you want me to revert the PR?