The Bug:

Trail ruins can generate with floating suspicious gravel blocks, causing suspicious gravel to be unintentionally destroyed.

Suspicious gravel and sand are destroyed when they fall. This makes it so that the player must be cautious when brushing, as one wrong move could result in the suspicious blocks being destroyed. Having suspicious gravel generate floating within trail ruins doesn't seem right, because as soon as these blocks receive a block update, they will fall and be destroyed.

Here is an example:

Seed: 8565983754514446683
Coordinates: /execute in minecraft:overworld run tp @s 13610.58 87.00 12688.70 -475.34 -21.90

Steps to Reproduce:

1. Generate a world with the seed provided above and teleport to the given coordinates.
2. Look closely at the floating suspicious gravel block.
3. Take note as to whether or not trail ruins can generate with floating suspicious gravel blocks, causing suspicious gravel to be unintentionally destroyed.

Observed Behavior:

Trail ruins can generate with floating suspicious gravel blocks, causing suspicious gravel to be unintentionally destroyed.

Expected Behavior:

Trail ruins would not be able to generate with floating suspicious gravel blocks. This would make it so that suspicious gravel wouldn't be unintentionally destroyed.