Adjust dictionary to use case-insensitive string comparer

Changed the `_aliasTypeDictionary` to use `StringComparer.OrdinalIgnoreCase`, ensuring that type aliases are not case-sensitive. This enhancement improves the robustness of type look-up operations.

src/modules/Elsa.Expressions/Services/WellKnownTypeRegistry.cs

@@ -7,7 +7,7 @@ namespace Elsa.Expressions.Services;
 /// <inheritdoc />
 public class WellKnownTypeRegistry : IWellKnownTypeRegistry
 {
-    private readonly Dictionary<string, Type> _aliasTypeDictionary = new();
+    private readonly Dictionary<string, Type> _aliasTypeDictionary = new(StringComparer.OrdinalIgnoreCase);
     private readonly Dictionary<Type, string> _typeAliasDictionary = new();
 
     /// <summary>