Add benchmark for async tree workloads

[arielin3]

What

Add a benchmark for testing async workloads, specifically an async tree workload that simulates simpler versions of a typical Instagram endpoint. ("typical implementation of endpoint in IG is an async function that in turn calls into numerous other async functions to generate an output." - see context below)

Motivation/Context

See python/cpython#91121

Testing

Running pyperformance locally:

% python3 -m pyperformance list
'<default>' benchmarks:
- 2to3
- async_tree
- async_tree_cpu_io_mixed
- async_tree_io
- async_tree_memoization
- chameleon
- chaos
...

% python3 -m pyperformance run -o ~/python_efficiency_hackamonth/pyperformance_async_tree_output.json --benchmarks=async_tree,async_tree_cpu_io_mixed,async_tree_memoization,async_tree_io
Python benchmark suite 1.0.5

Creating the virtual environment /Users/arielin/python_efficiency_hackamonth/pyperformance_git/pyperformance/venv/cpython3.10-38b51ccaf402-compat-c0d88e07feb9

...

Performance version: 1.0.5
Python version: 3.10.4 (64-bit) revision 9d38120e33
Report on macOS-12.3.1-x86_64-i386-64bit
Number of logical CPUs: 16
Start date: 2022-05-04 18:06:49.877751
End date: 2022-05-04 18:13:51.586338

### async_tree_none ###
Mean +- std dev: 830 ms +- 59 ms

### async_tree_cpu_io_mixed ###
Mean +- std dev: 1.10 sec +- 0.05 sec

### async_tree_io ###
Mean +- std dev: 2.00 sec +- 0.05 sec

### async_tree_memoization ###
Mean +- std dev: 963 ms +- 37 ms

(EDIT: Testing updated on 5/4 after rename changes)

[ericsnowcurrently]

Mostly LGTM.

[ericsnowcurrently]

I'll merge this tomorrow, after you've had a change to make any final changes.

[arielin3]

@ericsnowcurrently Thanks so much for the review! Updated and addressed all the comments :)

[arielin3]

@ericsnowcurrently It looks like the most recent test failure (test / ubuntu-latest - 3.11-dev) is due to the "sqlalchemy" benchmarks and not async tree related - it failed at creating venvs for that benchmarks, at

(43/53) creating venv for benchmark (sqlalchemy_declarative)
(44/53) creating venv for benchmark (sqlalchemy_imperative)

Are you able to rerun the failed test?

[ericsnowcurrently]

Yeah, it's not this PR.

[ericsnowcurrently]

Thanks for working on this!