Mask Sprite in Godot 4

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:bust_in_silhouette: Asked By cmdrsteel

How do I use a sprite to tell Godot I wish to mask part of another sprite? For Godot 3, we had Light2d. It had the mode option Mask. This did exactly what I wanted. However this option is no longer available in Godot 4, it is now just Add, Subtract, and Blend, and none of those options work for what I want. Any tips?