Dev shell tests with pytest

[dougch]

Resolved issues:

possible solution to #4056

Description of changes:

Wait for sslyze resolution in #4373

Move the bash checks for devShell utilities into pytest, and run it at the start of every nix develop run.

Call-outs:

For tests that are platform specific, this sets up a pytest marker to skip if we're running on an unsupported platform.
Note: the pytest marker only applies to this nix test, but could be added to integrationv2 in a future pr.

Testing:

How is this change tested (unit tests, fuzz tests, etc.)? locally. CI nix jobs will run this update as well.

on x86:

 nix develop .#awslc                                                                                                                                                         [00:01:34 2024-01-18]
Setting up awslc environment from flake.nix...
nix/shell.sh: Entering a devShell...checking environment.
======================================================================================= test session starts ========================================================================================
platform linux -- Python 3.10.9, pytest-7.1.3, pluggy-1.0.0 -- /nix/store/d34dvggnx2qsa2kc23hzxgwn2bmh8fgg-python3-3.10.9-env/bin/python3.10
cachedir: .pytest_cache
rootdir: /home/dougch/gitrepos/s2n-tls/nix, configfile: pytest.ini
plugins: forked-1.4.0, xdist-2.5.0, rerunfailures-10.2
collected 10 items                                                                                                                                                                                 

nix/test_devshell.py::test_s2n_libcrypto[awslc] PASSED                                                                                                                                       [ 10%]
nix/test_devshell.py::test_s2n_libcrypto_uniq[awslc] PASSED                                                                                                                                  [ 20%]
nix/test_devshell.py::test_utility_versions[gnutls-serv-gnutls-serv 3.7---version] PASSED                                                                                                    [ 30%]
nix/test_devshell.py::test_utility_versions[gnutls-cli-gnutls-cli 3.7---version] PASSED                                                                                                      [ 40%]
nix/test_devshell.py::test_utility_versions[openssl-OpenSSL 1.1.1-version] PASSED                                                                                                            [ 50%]
nix/test_devshell.py::test_utility_versions[java-Corretto-17---version] PASSED                                                                                                               [ 60%]
nix/test_devshell.py::test_python PASSED                                                                                                                                                     [ 70%]
nix/test_devshell.py::test_pytest PASSED                                                                                                                                                     [ 80%]
nix/test_devshell.py::test_sslyze PASSED                                                                                                                                                     [ 90%]
nix/test_devshell.py::test_nassl PASSED                                                                                                                                                      [100%]

======================================================================================== 10 passed in 0.06s ========================================================================================
[nix awslc] dougch@devdesktop22:~/gitrepos/s2n-tls$ 

on aarch64, only the last two lines differ:

nix/test_env.py::test_sslyze SKIPPED (platform specific test; not running on aarch64)                                                                                                                          [ 90%]
nix/test_env.py::test_nassl SKIPPED (platform specific test; not running on aarch64)                                                                                                                           

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[github-actions]

This PR has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.