Fix: only count distance traveled in vehicles for cargo payment (#11283)

No longer you can utilize the free (and instant) labour of station
workers, transporting your cargo from one part of the station to
the other. No more!

Based on patch by dP.

(cherry picked from commit df400ef84a)

src/sl/extended_ver_sl.cpp

@@ -206,6 +206,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_DISASTER_VEH_STATE,               XSCF_NULL,                1,   1, "slv_disaster_veh_state",           nullptr, nullptr, nullptr          },
 	{ XSLFI_SAVEGAME_ID,                      XSCF_NULL,                1,   1, "slv_savegame_id",                  nullptr, nullptr, nullptr          },
 	{ XSLFI_NEWGRF_LAST_SERVICE,              XSCF_NULL,                1,   1, "slv_newgrf_last_service",          nullptr, nullptr, nullptr          },
+	{ XSLFI_CARGO_TRAVELLED,                  XSCF_NULL,                1,   1, "slv_cargo_travelled",              nullptr, nullptr, nullptr          },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, nullptr, nullptr, nullptr, nullptr },// This is the end marker
 };