Noise artifacts on the cloud when reconstructNormal is enabled

[shotamatsuda]

Reproduces on the clouds when viewed from above toward the ground with reconstructNormal enabled.

[shotamatsuda]

It is caused by the early exit, which breaks the differential for normal derivation.
https://github.com/takram-design-engineering/three-geospatial/blob/main/packages/atmosphere/src/shaders/aerialPerspectiveEffect.frag#L257