Fix memory leak when using custom renderers in wxOSX wxDataViewCtrl.

wxDataViewRendererNativeData retains a reference to the cell passed to it, so
the cell must be released after passing it to wxDataViewRendererNativeData to
avoid leaking it.

Closes #16226.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76637 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/osx/cocoa/dataview.mm

@@ -2755,7 +2755,9 @@ wxDataViewCustomRenderer::wxDataViewCustomRenderer(const wxString& varianttype,
       m_editorCtrlPtr(NULL),
       m_DCPtr(NULL)
 {
-    SetNativeData(new wxDataViewRendererNativeData([[wxCustomCell alloc] init]));
+    wxCustomCell* cell = [[wxCustomCell alloc] init];
+    SetNativeData(new wxDataViewRendererNativeData(cell));
+    [cell release];
 }
 
 bool wxDataViewCustomRenderer::MacRender()