Non-full blocks that aren't solid can block the Warden from spawning

Related to MC-250353
Non-full blocks that isn't solid such as snow layers, redstone wires, and strings can block the Warden from being spawned.

How to Reproduce

1. Make a platform in the sky (Doesn't have to be big)
2. Place a sculk shrieker next to the platform with this command:
   /setblock ~ ~ ~ sculk_shrieker["can_summon": true]
3. Place non-full block that isn't solid such as strings or snow layers to cover the platform
4. Switch the time to midnight
5. Try to summon the warden by stepping on the shrieker (at least 3 or 4 times)

Observed Result
The Warden cannot spawn at all

Expected Result
The Warden should be able to spawn on it.