Min Cores / Slots for process

[chris-smith-zocdoc]

Is your feature request related to a problem? Please describe.
We have some heavy integration tests that require more than 1 cpu core to be available to run reliably.

I understand Bazel has a similar feature but I have no experience with it

Tests are granted at least one CPU core. Others may be available but this is not guaranteed. Other performance aspects of this core are not specified. You can increase the reservation to a higher number of CPU cores by adding the tag "cpu:n" (where n is a positive number) to a test rule. If a machine has less total CPU cores than requested, Bazel will still run the test. If a test uses sharding, each individual shard will reserve the number of CPU cores specified here.

Similar conversations in slack
https://pantsbuild.slack.com/archives/C046T6T9U/p1651770597838669

Related Issues
#15482 (comment)

Describe the solution you'd like
I'd like to express this requirement in the target directly (or inferred in our heuristic in our plugin). Ultimately I think this could be treated similarly to concurrency_available but it needs to be a constant value instead of a suggestion.

Describe alternatives you've considered
As a work around we need to manually include/exclude certain targets or use --process-parallelism but that has the negative side effect of modifying the entire run, not just the resource heavy steps