Plants without support are destroyed when loading chunks in existing marketplace worlds

Partner Rank: 2

Verification builds: 1.21.0, 1.21.30.21
Regression builds: 1.20.81

Summary: In some of our maps, we used world editing software to place plants in places where they can't normally go, like sugar cane not placed next to water. Previously, this worked fine. In the current version, loading these chunks breaks all of these blocks, spewing items everywhere.

Impact: Massive frame drops and potential crashes on weak devices. Previously working worlds can suddenly become unplayable. This affects multiple worlds on the store.

Repro Steps:

1. Download and open "Nether Monster Hunter" from the marketplace
2. /tp 2254 52 18 and fly around

Expected Results: Field of sugar cane remains intact
Observed Results: Field of sugar cane explodes into a billion items, utterly destroying the framerate

Screenshots/Videos attached: Yes