Move simulator settings disposal earlier so it happens before parent.

Fixes https://gitlab.com/kicad/code/kicad/issues/12370

eeschema/sim/sim_plot_frame.cpp

@@ -239,8 +239,6 @@ SIM_PLOT_FRAME::~SIM_PLOT_FRAME()
 {
     NULL_REPORTER devnull;
 
-    m_simulator->Settings() = nullptr;
-
     m_simulator->Attach( nullptr, devnull );
     m_simulator->SetReporter( nullptr );
     delete m_reporter;
@@ -1694,6 +1692,9 @@ void SIM_PLOT_FRAME::doCloseWindow()
     m_schematicFrame->GetToolManager()->RunAction( ACTIONS::cancelInteractive );
 
     SaveSettings( config() );
+
+    m_simulator->Settings() = nullptr;
+
     Destroy();
 }