Revert "Add the revision to SDL_version.h"

This reverts commit a3992f504cf70b4fb3e4d66fa954ddd545c4609b.

The reason SDL_revision.h was not included by SDL.h or SDL_version.h is because SDL_revision.h changes with every git commit, causing a complete SDL rebuild for every trivial git commit.

include/SDL3/SDL_version.h

@@ -30,7 +30,6 @@
 #define SDL_version_h_
 
 #include <SDL3/SDL_stdinc.h>
-#include <SDL3/SDL_revision.h>
 
 #include <SDL3/SDL_begin_code.h>
 /* Set up for C function definitions, even when using C++ */