Invalidate wxOwnerDrawnComboBox best size after adding new items

The previously computed best size may become invalid after inserting new
items, so forget it.

See #23681.

(cherry picked from commit a9d2a140900f8214f7d724889fcf9f06c27db7d2)

docs/changes.txt

@@ -263,6 +263,7 @@ All (GUI):
 - Fix crash when loading some mal-formed GIFs (PB, #23409).
 - Relax checks on character entry in numeric validators (#12968, #23561).
 - Fix wxRibbonToolBar::GetToolByPos() and DeleteToolByPos() (mcorino, #23457).
+- Update wxOwnerDrawnComboBox best size when adding items (Reza Karimi, #23681).
 
 wxGTK:
 

src/generic/odcombo.cpp

@@ -1112,6 +1112,7 @@ int wxOwnerDrawnComboBox::DoInsertItems(const wxArrayStringsAdapter& items,
             AssignNewItemClientData(n, clientData, i, type);
         }
 
+        InvalidateBestSize();
         return n;
     }
     else
@@ -1122,6 +1123,7 @@ int wxOwnerDrawnComboBox::DoInsertItems(const wxArrayStringsAdapter& items,
             AssignNewItemClientData(pos, clientData, i, type);
         }
 
+        InvalidateBestSize();
         return pos - 1;
     }
 }