Adding NUMBA_MLIR_USE_DPNP to setup.py, environment.yml and setenv.sh

[chudur-budur]

• A small modification so that NUMBA_MLIR_USE_DPNP could be used from bash environment variable.
• setup.py can compile with dpctl headers if NUMBA_MLIR_USE_DPNP=1
• Adding environment.yml and setenv.sh so that environment replication becomes easy and fast.

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[Hardcode84]

I'm ok with setup.py changes, although be don't need them immediately, but evironment.yaml and setup.sh just captures your local environment, I don't think we want to keep them in repo.

[chudur-budur]

I'm ok with setup.py changes, although be don't need them immediately, but evironment.yaml and setup.sh just captures your local environment, I don't think we want to keep them in repo.

Okay, fixed it.

[Hardcode84]

pls, fix precommit

[chudur-budur]

converting into draft, since I am doing several modifications in the setup.py so that it can be built in-tree in numba-dpex
please do not merge (now or sooner)