Pass configured Python interpreter in to use for BOM plugins

Fixes https://gitlab.com/kicad/code/kicad/-/issues/8594

CMakeModules/config.h.cmake

@@ -99,4 +99,7 @@
 /// When pkg-config config is not available for ngspice, use ngspice/config.h for version.
 #cmakedefine NGSPICE_HAVE_CONFIG_H
 
+/// Path to the python executable that should be used by KiCad
+#define PYTHON_EXECUTABLE               "@PYTHON_EXECUTABLE@"
+
 #endif  // CONFIG_H_

eeschema/bom_plugins.cpp

@@ -23,6 +23,7 @@
  */
 
 #include "bom_plugins.h"
+#include <config.h>
 #include <paths.h>
 #include <wx/ffile.h>
 #include <wx/log.h>
@@ -70,7 +71,12 @@ BOM_GENERATOR_HANDLER::BOM_GENERATOR_HANDLER( const wxString& aFile )
                                   m_file.GetPath(), m_file.GetFullName(),
                                   getOutputExtension( m_info ) );
 #else
-        m_cmd = wxString::Format( "python \"%s\" \"%%I\" \"%%O%s\"", m_file.GetFullPath(),
+        wxString interpreter = wxString::FromUTF8Unchecked( PYTHON_EXECUTABLE );
+
+        if( interpreter.IsEmpty() )
+            interpreter = wxT( "python" );
+
+        m_cmd = wxString::Format( "%s \"%s\" \"%%I\" \"%%O%s\"", interpreter, m_file.GetFullPath(),
                                   getOutputExtension( m_info ) );
 #endif
     }