iOS Supported version mismatching

[TheJarX]

Describe the bug

An error is triggered when trying to run on iOS a mismatch in the supported versions of iOS in these two files:

• https://github.com/AvaloniaUI/avalonia-dotnet-templates/blob/master/templates/csharp/xplat/AvaloniaTest.iOS/Info.plist#L16
• https://github.com/AvaloniaUI/avalonia-dotnet-templates/blob/master/templates/csharp/xplat/AvaloniaTest.iOS/AvaloniaTest.iOS.csproj#L5

Related to: PR #209

To Reproduce

• Create a project with the xplat template
• Open and try to run on iOS

Avalonia Templates version

11.0.0

Avalonia version

11.0.0

Additional context

Info.plist: The MinimumOSVersion value in the Info.plist (10.0) does not match the SupportedOSPlatformVersion value (13.0) in the project file (if there is no SupportedOSPlatformVersion value in the project file, then a default value has been assumed). Either change the value in the Info.plist to match the SupportedOSPlatformVersion value, or remove the value in the Info.plist (and add a SupportedOSPlatformVersion value to the project file if it doesn't already exist).