Port SDL3 release scripts to SDL2

[skip ci]

VisualC/pkg-support/cmake/sdl2-config.cmake

@@ -79,6 +79,8 @@ endif()
 unset(_sdl2_library)
 unset(_sdl2_dll_library)
 
+set(SDL2_SDL2-static_FOUND FALSE)
+
 set(_sdl2main_library "${SDL2_LIBDIR}/SDL2main.lib")
 if(EXISTS "${_sdl2main_library}")
     if(NOT TARGET SDL2::SDL2main)
@@ -110,7 +112,7 @@ if(EXISTS "${_sdl2test_library}")
     endif()
     set(SDL2_SDL2test_FOUND TRUE)
 else()
-    set(SDL2_SDL2_FOUND FALSE)
+    set(SDL2_SDL2test_FOUND FALSE)
 endif()
 unset(_sdl2test_library)