Swap SDLmain lib for SDL_main.h #40

Job	Run time
build (ubuntu-latest, Release, gcc)	3m 40s
build (ubuntu-latest, Release, clang)	3m 18s
build (ubuntu-latest, Release, mingw-w64-gcc)	3m 6s
build (ubuntu-latest, Debug, gcc)	4m 14s
build (ubuntu-latest, Debug, clang)	2m 45s
build (ubuntu-latest, Debug, mingw-w64-gcc)	2m 50s
build (windows-latest, Release, cl)	4m 31s
build (windows-latest, Debug, cl)	4m 26s
build (macos-latest, Release, gcc)	2m 58s
build (macos-latest, Release, clang)	2m 38s
build (macos-latest, Debug, gcc)	2m 45s
build (macos-latest, Debug, clang)	2m 36s
	39m 47s

Provide feedback