Make `bevy_ui` and `bevy_camera` optional deps for `bevy_input_focus` #51326

Job	Run time
build-without-default-features-status	0s
run-examples-on-wasm	0s
check-example-showcase-patches-still-work	0s
build-and-install-on-iOS	0s
build-android	0s
check-unused-dependencies	-6s
build-without-default-features	-8s
	-14s

Provide feedback