Add missing SDL_main.h includes to remaining libSDLmain implementations

this should hopefully make the automated builds work again

(this commit can probably be removed once all affected platforms are
converted to header-only SDL_main)

src/main/dummy/SDL_dummy_main.c

@@ -2,6 +2,7 @@
     SDL_dummy_main.c, placed in the public domain by Sam Lantinga  3/13/14
 */
 #include <SDL3/SDL.h>
+#include <SDL3/SDL_main.h> /* until this SDL_main impl is converted to header-only.. */
 
 #ifdef main
 #undef main

src/main/gdk/SDL_gdk_main.c

@@ -19,6 +19,7 @@
   3. This notice may not be removed or altered from any source distribution.
 */
 #include <SDL3/SDL.h>
+#include <SDL3/SDL_main.h> /* until this SDL_main impl is converted to header-only.. */
 
 /* Include this so we define UNICODE properly */
 #include "../../core/windows/SDL_windows.h"

src/main/n3ds/SDL_n3ds_main.c

@@ -19,6 +19,7 @@
   3. This notice may not be removed or altered from any source distribution.
 */
 #include <SDL3/SDL.h>
+#include <SDL3/SDL_main.h> /* until this SDL_main impl is converted to header-only.. */
 
 #ifdef __3DS__
 

src/main/ngage/SDL_ngage_main.cpp

@@ -2,6 +2,7 @@
     SDL_ngage_main.c, originally for SDL 1.2 by Hannu Viitala
 */
 #include <SDL3/SDL.h>
+#include <SDL3/SDL_main.h> /* until this SDL_main impl is converted to header-only.. */
 
 #include <e32std.h>
 #include <e32def.h>

src/main/ps2/SDL_ps2_main.c

@@ -2,6 +2,7 @@
     SDL_ps2_main.c, fjtrujy@gmail.com
 */
 #include <SDL3/SDL.h>
+#include <SDL3/SDL_main.h> /* until this SDL_main impl is converted to header-only.. */
 
 #ifdef __PS2__
 

src/main/psp/SDL_psp_main.c

@@ -2,6 +2,7 @@
     SDL_psp_main.c, placed in the public domain by Sam Lantinga  3/13/14
 */
 #include <SDL3/SDL.h>
+#include <SDL3/SDL_main.h> /* until this SDL_main impl is converted to header-only.. */
 
 #ifdef __PSP__
 

src/main/uikit/SDL_uikit_main.c

@@ -2,6 +2,7 @@
     SDL_uikit_main.c, placed in the public domain by Sam Lantinga  3/18/2019
 */
 #include <SDL3/SDL.h>
+#include <SDL3/SDL_main.h> /* until this SDL_main impl is converted to header-only.. */
 
 #if defined(__IOS__) || defined(__TVOS__)
 

src/main/winrt/SDL_winrt_main_NonXAML.cpp

@@ -2,6 +2,7 @@
     SDL_winrt_main_NonXAML.cpp, placed in the public domain by David Ludwig  3/13/14
 */
 #include <SDL3/SDL.h>
+#include <SDL3/SDL_main.h> /* until this SDL_main impl is converted to header-only.. */
 
 #include <wrl.h>