Also trim board item layersets.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/20063

pcbnew/drc/drc_test_provider_library_parity.cpp

@@ -297,7 +297,8 @@ bool padNeedsUpdate( const PAD* a, const PAD* b, REPORTER* aReporter )
     if( a->GetRemoveUnconnected() )
         layerSettingsDiffer |= a->GetKeepTopBottom() != b->GetKeepTopBottom();
 
-    if( layerSettingsDiffer || a->GetLayerSet() != getBoardNormalizedLayerSet( b, a->GetBoard() ) )
+    if( layerSettingsDiffer
+            || getBoardNormalizedLayerSet( a, a->GetBoard() ) != getBoardNormalizedLayerSet( b, a->GetBoard() ) )
     {
         diff = true;