Enabling render and viewport denoising is now both done from the render properties. View layers still can individually be enabled/disabled for denoising and have their own denoising parameters. Note that the denoising engine also affects how denoising data passes are output even if no denoising happens on the render itself, to make the passes compatible with the engine. This includes internal refactoring for how denoising parameters are passed along, trying to avoid code duplication and unclear naming. Ref T76259