chores: update to LUA 5.3 (#4203)

Co-authored-by: Peter Feerick <peter.feerick@gmail.com>
Co-authored-by: philmoz <phil.a.mitchell@gmail.com>

radio/src/tests/lua.cpp

@@ -26,6 +26,7 @@
 
 #define SWAP_DEFINED
 #include "edgetx.h"
+#include "lua/lua_states.h"
 
 #define MIXSRC_THR     (MIXSRC_FIRST_STICK + inputMappingGetThrottle())
 #define MIXSRC_TRIMTHR (MIXSRC_FIRST_TRIM + inputMappingGetThrottle())
@@ -189,6 +190,11 @@ TEST(Lua, Switches)
 {
   luaExecStr("if MIXSRC_SA == nil then error('failed') end");
   luaExecStr("if MIXSRC_SB == nil then error('failed') end");
+#if defined(SURFACE_RADIO)
+  luaExecStr("if getSwitchIndex('St-') == nil then error('failed') end");
+#else
+  luaExecStr("if getSwitchIndex('Rud-') == nil then error('failed') end");
+#endif
 }
 
 TEST(Lua, testLegacyNames)