Parity issue: Bedrock pattern at the bottom of the Overworld is not the same across editions

1.18 changes the bedrock at the bottom of the world such that it depends on the world seed. 1.18 also aims to have world generation match as closely as possible in Java Edition and Bedrock Edition. However, using the same seed on both editions and clearing out an area to expose the topmost level of bedrock shows a different pattern created by said bedrock, even though it'd be expected they'd be the same.