C# diagnostics GD0103 and GD0104 are reported twice for properties

[a-johnston]

Tested versions

Introduced by #67304 starting in 4.2

System information

n/a

Issue description

Given the code

[Export] public string Foo { set => foo = value; }

[Export] public string Bar { get; }

the diagnostic errors for read only and write only property exports are raised twice:

due to ScriptPropertiesGenerator.cs previously having relied on WhereIsGodotCompatibleType to filter those cases out. The errors are otherwise raised ScriptPropertyDefValGenerator.cs alongside other export property checks.

The easy fix would be to keep the early return in DeterminePropertyInfo but removing the ReportDiagnostic calls and changing the comments to indicate that case is handled by a different generator class. Ideally IMO there wouldn't be multiple classes deriving the same information and doing the same validation to begin with but that is a different issue.

Steps to reproduce

Try to export a read only or write only property.

Minimal reproduction project (MRP)

n/a