Add macOS test flow to automation

[sigalsax]

Now that the macos executor is available to us in our pipeline, we should add it so that we are constantly testing our additions on multiple platforms.

See our contributing docs for an explanation on how to build and run our tests

DOD

• Evaluate if the macos executor has a keychain. If not, talk to infra/research on how to proceed b/c our tests use the macOS keychain
• Add the ability to run our integration and unit tests to our pipeline in it's own stage