Pad editor dlg: set the default thermal spoke to 90 deg for RR pad shape

It was 45 deg, but this default value is good for round pads only, not
for rectangular pad shapes.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/21271

(cherry picked from commit cef15bcf30)

pcbnew/board_design_settings.cpp

@@ -1554,4 +1554,9 @@ void BOARD_DESIGN_SETTINGS::SetDefaultMasterPad()
 
     constexpr double RR_RADIUS = DEFAULT_PAD_HEIGTH_MM * DEFAULT_PAD_RR_RADIUS_RATIO;
     m_Pad_Master->SetRoundRectCornerRadius( PADSTACK::ALL_LAYERS, pcbIUScale.mmToIU( RR_RADIUS ) );
+
+    if( m_Pad_Master->GetFrontShape() == PAD_SHAPE::CIRCLE )
+        m_Pad_Master->SetThermalSpokeAngle( ANGLE_45 );
+    else
+        m_Pad_Master->SetThermalSpokeAngle( ANGLE_90 );
 }