test: remove obsolete test for SetSharp section handling

The test was verifying behavior that is no longer relevant as SetSharp section handling has been removed from the codebase.

Author: Amirhossein Beheshti

tests/SetSharp.Tests/ModelBuilder/ConfigurationModelBuilderTests.cs

@@ -34,28 +34,6 @@ public void BuildFrom_WithFlatPrimitives_ShouldCreateModelCorrectly()
             Assert.Equal("double", rootModel.Properties.First(p => p.PropertyName == "DefaultThreshold").PropertyType);
         }
 
-        [Fact]
-        public void BuildFrom_WithSetSharpSection_ShouldIgnoreSetSharp()
-        {
-            // Arrange
-            var builder = new ConfigurationModelBuilder();
-            var root = new Dictionary<string, object>
-            {
-                { "ConnectionString", "Server=.;Database=Test;"},
-                { "SetSharp", new Dictionary<string, object>() }
-            };
-
-            // Act
-            var result = builder.BuildFrom(root);
-
-            // Assert
-            var rootModel = Assert.Single(result);
-            Assert.Equal("RootOptions", rootModel.ClassName);
-            Assert.Equal("", rootModel.SectionPath);
-
-            Assert.DoesNotContain(result, c => c.ClassName == "SetSharp");
-        }
-
         [Fact]
         public void BuildFrom_WithNestedObject_ShouldCreateSeparateClassModel()
         {