GitHub Actions: macOS virtual environment updated to Catalina

The GitHub Actions macOS virtual environment has been upgraded to Catalina (v10.15). Jobs using the macos-10.14 virtual environment will not run and must be migrated to use macos-latest.

In addition to Catalina, other changes include:

• Xcode 11.1 will be set as default
• Mono 6.4, Xamarin.iOS 13.4, Xamarin.Android 10.0, Xamarin.Mac 6.2 will be set as default
• .NET Core 3.0 will be set as default
• Node.JS 12 will be set as default
• Removed Xamarin.iOS 13.2
• Removed Xamarin.iOS SDK 12.*
• Removed Xamarin.iOS SDK 11.*
• Removed Xamarin.iOS SDK 10.*
• Removed Xamarin.Android SDK 9.*
• Removed Xamarin.Android SDK 8.*
• Removed Xamarin.Android SDK 7.*
• Removed Xamarin.Mac SDK – 5.*
• Removed Xamarin.Mac SDK – 4.*
• Removed Xamarin.Mac SDK – 3.*
• Removed Mono 4.x
• Removed Mono 5.x
• Removed Mono 6.0
• Removed Xcode 10.*
• Removed Xcode 9.*
• Removed legacy iOS Simulators (iOS 8.4 – 10.2)
• Removed .NET Core 2.x (only 3.x are on image)
• Removed Android build tools less than 24.0.0

To learn more about the different virtual environments and included software, please read Virtual Environments for GitHub Actions. Also, please contact GitHub Support if you run into any problems or need help.