[release/8.0] Fix PropertyGrid.RemoveTabType method (#10589)

* Fix RemoveTabType method

* Add unit test

---------

Co-authored-by: thomasnaletsg <155535130+thomasnaletsg@users.noreply.github.com>
Co-authored-by: Loni Tra <lonitra@microsoft.com>

src/System.Windows.Forms/src/System/Windows/Forms/PropertyGrid.cs

@@ -3580,7 +3580,7 @@ internal void RemoveTab(Type tabType)
         int tabIndex = -1;
         for (int i = 0; i < _tabs.Count; i++)
         {
-            if (tabType == _tabs[i].GetType())
+            if (tabType == _tabs[i].Tab.GetType())
             {
                 tabIndex = i;
                 break;

src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/PropertyGridTests.cs

@@ -11,6 +11,7 @@
 using Moq;
 using Point = System.Drawing.Point;
 using Size = System.Drawing.Size;
+using System.Windows.Forms.Design;
 
 namespace System.Windows.Forms.Tests;
 
@@ -2357,6 +2358,28 @@ public void PropertyGrid_PropertySort_SetWithHandle_GetReturnsExpected(PropertyS
         Assert.Equal(0, createdCallCount);
     }
 
+    [WinFormsFact]
+    public void PropertyGrid_PropertyTabCollection_AddAndRemoveTabType_Success()
+    {
+        using PropertyGrid grid = new();
+        Assert.Equal(1, grid.PropertyTabs.Count);
+
+        grid.PropertyTabs.AddTabType(typeof(TestPropertyTab));
+        Assert.Equal(2, grid.PropertyTabs.Count);
+
+        grid.PropertyTabs.RemoveTabType(typeof(TestPropertyTab));
+        Assert.Equal(1, grid.PropertyTabs.Count);
+    }
+
+    private class TestPropertyTab : PropertyTab
+    {
+        public override string TabName => "TestTabName";
+
+        public override Bitmap Bitmap => new(10, 10);
+
+        public override PropertyDescriptorCollection GetProperties(object component, Attribute[] attributes) => throw new NotImplementedException();
+    }
+
     [WinFormsFact]
     public void PropertyGrid_SelectedGridItem_SetNull_ThrowsArgumentNullException()
     {