setup.sh has a few failures with conda activation, cuda versioning, flash attn and pillow-simd requirements #111

Minor issues on the install when run as as ./setup.sh with options:

--new-env 

conda is not initalized in shells so trellis gets installed in current env.

--basic    

pillow-simd installation can fail, some reqd pkgs, libjpeg-turbo zlib gxx_linux-64 are missing,

• results in double pillow and pillow-simd installations
• if using conda, links to both conda and system libs

--flash-attn 

errs on `No Module Named 'torch' Dao-AILab/flash-attention#246

"$PLATFORM" = "cuda" with   --new-env  and   --flexgemm | --nvdiffrast  | --nvdiffrec 

If machine CUDA != torch cuda, these fail, as they require compiling against torch's cuda version.

Env. Ubuntu 24.04 + Conda + Nvidia A6000 + Cuda 13.0