[Web][CI] Add mock function implementations (navigator.getGamepads())
[Web][CI] Add mock function implementations (navigator.getGamepads())

Siv3D/OpenSiv3D,Siv3D/OpenSiv3D,Siv3D/OpenSiv3D,Siv3D/OpenSiv3D,Siv3D/OpenSiv3D,Siv3D/OpenSiv3D