Bump dosbox-x. Fix zandronum version. Preparing to repair SDL3.

Update dosbox-x to release 2025.01.01.

Fix incorrect version for zandronum alpha.

Prepar fix for SDL3 [#116997.](https://github.com/libsdl-org/SDL/issues/11697)

media-libs/libsdl3/files/libsdl3-3.1.6-fix_sdl_gl_getattribute.patch

@@ -0,0 +1,22 @@
+--- a/src/video/SDL_video.c	2024-10-24 01:50:52.000000000 +0300
++++ b/src/video/SDL_video.c	2024-12-29 08:36:06.900299900 +0200
+@@ -4909,6 +4931,19 @@
+         }
+         return SDL_SetError("OpenGL error: %08X", error);
+     }
++
++    // convert GL_CONTEXT_RELEASE_BEHAVIOR values back to SDL_GL_CONTEXT_RELEASE_BEHAVIOR values
++#ifdef SDL_VIDEO_OPENGL
++    if (attr == SDL_GL_CONTEXT_RELEASE_BEHAVIOR) {
++        *value = *value == GL_CONTEXT_RELEASE_BEHAVIOR_FLUSH ? SDL_GL_CONTEXT_RELEASE_BEHAVIOR_FLUSH : SDL_GL_CONTEXT_RELEASE_BEHAVIOR_NONE;
++    }
++#else
++    if (attr == GL_CONTEXT_RELEASE_BEHAVIOR_KHR) {
++        *value = *value == GL_CONTEXT_RELEASE_BEHAVIOR_FLUSH_KHR ? SDL_GL_CONTEXT_RELEASE_BEHAVIOR_FLUSH : SDL_GL_CONTEXT_RELEASE_BEHAVIOR_NONE;
++    }
++    attrib = GL_CONTEXT_RELEASE_BEHAVIOR_KHR;
++#endif
++
+     return true;
+ #else
+     return SDL_Unsupported();