Revert the spawning mechanics in 1.17.30.20 beta to match previous versions

in the 1.17.30.20 beta, spawning mechanics of ghast were changed so that if a non solid block was in the hitbox of the mob when spawning, the mob would be instantly pushed down, and if the mob then still has a block in its hitbox, the spawn attempt will be cancelled and the mob would not spawn, this is a pretty big issue that breaks multiple farms. Additionally, the bug report that caused the change [MCPE-133687] seems to be created with information about spawn proofing areas for Java Edition and not Bedrock Edition, where a mechanic commonly known as instapush exists and has been widely used.