Remove llvmdev from runtime dependecies

[reazulhoque]

This PR updates the runtime dependencies specified in the conda recipe.

1. Remove llvmdev as we do not use opt to generate LLVM bitcode.
2. Introduce packaging as it is being used in numba_dppy/config.py.

@PokhodenkoSA Do we need to use packaging here or can it be accomplished somehow else?

[PokhodenkoSA]

@reazulhoque please provide PR where it started:

1. ... we do not use opt to generate LLVM bitcode.

From this:

2. Introduce packaging as it is being used in numba_dppy/config.py.

As I understand llvmdev depends on packaging. So now llvmdev is not used but packaging is needed. Correct?

If yes then I think the changes are good.

[reazulhoque]

@PokhodenkoSA I do not see packaging as a dependency even when we have llvmdev as a runtime dependency. Both the points are applicable to this PR.