Fix CI for macos-latest

[martincostello]

Since the macos-latest label changed from macOS 12 with x64 to macOS 14 on arm64, the macOS tests are failing or hanging.

#2079 fixed failures due to .NET 6 missing, but since that was merged tests appear to be intermittently hanging for some reason.

Need to investigate and resolves.

[martincostello]

The original problem seems to have gone away and it's not completely broken now.