Test a binary in benchpark

[pearce8]

@scheibelp please add your thoughts on how to use Spack to do this.

Sys admins want to test a pre-built binary as system software changes

Examples:

• MPI was re-installed
• Libraries disappeared

We could have an existing workspace/prefix where these binaries live.

ramble on both builds and runs. So we would need an experiment (or experiment + modifier) that choses a package manager that will not build, but will retrieve the binary (see #601 maybe for the apptainer modifier that might be skipping the build as well and download the binary).

Features from benchpark that are useful in this request:

• Benchmarks (representatives of user workloads)
• CI
• Performance comparison