Explicitly specify the Catalina operating system version and update the default Xcode version in the test suite Workflow

[jaebradley]

Summary

While the macos-latest GitHub Actions workflow label still is a valid reference for the macOS Catalina 10.15 virtual environment, with the advent of macOS Big Sur 11.x macos-latest may be a confusing label to use.

It might be clearer to simply use the explicit workflow label containing the major + minor version.

Additionally, this PR updates the job name, as the latest default Xcode version to ship with the macos-10.15 environment is actually 12.0.1 (and not 11 as the job name would suggest).

See: actions/runner-images#2056 and https://github.com/actions/virtual-environments/blob/main/images/macos/macos-10.15-Readme.md#xcode

Issues When Attempting To Add Big Sur Job

As part of the changes in this PR, I wanted to also add some tests for Big Sur but failed to complete this task with a passing build.

What I found was interesting (and I could definitely be doing something incorrectly).

It is interesting to note that the the default Xcode version for the macos-11.0 GitHub Actions workflow label is 11.7.

Attempt adding macos-11.0 job without setting Xcode to 12.2 explicitly

When the job using Big Sur with the default Xcode version runs its configuration step, I see the following errors

Additional data:

• That specific workflow's raw logs
• That specific GitHub Actions Workflow
• The commit associated with that workflow
• Can verify that the macos-11.0 environment has a default Xcode version of 11.7 by looking at the output of xcodebuild -version for this failed configuration step

Attempt adding macos-11.0 job after setting Xcode to 12.2 explicitly

After sudo xcode select-ing /Applications/Xcode_12.2.app, the configuration step runs successfully, but I see a test failure

Additional data:

• That specific workflow's raw logs
• That specific GitHub Actions Workflow
• The commit associated with the workflow

Hopefully this section on investigating trying to add a job for Big Sur makes sense and is at least somewhat coherent. I could very well be doing something incorrectly but was hoping to get some feedback on what that "something" is, if possible.

[karenetheridge]

This is excellent! thank you very much.