.github/workflows: remove SDL2_gfx test build as the download link has expired certificate
.github/workflows: remove SDL2_gfx test build as the download link has expired certificate

Signed-off-by: Lilis Iskandar <f9acb790f2c75b127492316321ece0121b8eed9b@veand.co>

veandco/go-sdl2,veandco/go-sdl2