Merge branch 'master' into jgrpp

# Conflicts:
#	.github/workflows/release-linux.yml
#	src/base_consist.h
#	src/blitter/32bpp_optimized.cpp
#	src/blitter/32bpp_optimized.hpp
#	src/blitter/32bpp_sse2.hpp
#	src/blitter/8bpp_optimized.hpp
#	src/gfx_func.h
#	src/industry_cmd.cpp
#	src/industrytype.h
#	src/linkgraph/linkgraphjob.cpp
#	src/mixer.cpp
#	src/newgrf_callbacks.h
#	src/openttd.cpp
#	src/os/macosx/macos.mm
#	src/os/windows/win32.cpp
#	src/pathfinder/npf/npf.cpp
#	src/road_cmd.cpp
#	src/saveload/afterload.cpp
#	src/saveload/saveload.h
#	src/saveload/vehicle_sl.cpp
#	src/sound.cpp
#	src/spritecache.cpp
#	src/spriteloader/spriteloader.hpp
#	src/station_map.h
#	src/timetable_cmd.cpp
#	src/timetable_cmd.h
#	src/timetable_gui.cpp
#	src/town_cmd.cpp
#	src/vehicle_cmd.cpp
#	src/vehicle_gui_base.h
#	src/video/opengl.cpp
#	src/video/opengl.h
#	src/viewport.cpp

src/newgrf_callbacks.h

@@ -283,6 +283,9 @@ enum CallbackID {
 	/** Called to determine the engine name to show. */
 	CBID_VEHICLE_NAME                    = 0x161, // 15 bit callback
 
+	/** Called to determine probability during build. */
+	CBID_VEHICLE_BUILD_PROBABILITY       = 0x162, // 15 bit callback
+
 	/** Extended/non-standard callbacks follow */
 
 	/** Called to set town zones */