sbpack_nf missing requirements

[dmiller15]

Following the normal installation guidelines, pipx will fail to build a functional executor for spack_nf. See the error below:

> sbpack_nf
Traceback (most recent call last):
  File "/Users/millerd15/.local/bin/sbpack_nf", line 5, in <module>
    from sbpack.noncwl.nextflow import main
  File "/Users/millerd15/.local/pipx/venvs/sbpack/lib/python3.12/site-packages/sbpack/noncwl/nextflow.py", line 10, in <module>
    from nf_core.schema import PipelineSchema
  File "/Users/millerd15/.local/pipx/venvs/sbpack/lib/python3.12/site-packages/nf_core/__init__.py", line 7, in <module>
    import pkg_resources
ModuleNotFoundError: No module named 'pkg_resources'

Updating the requirements file with setuptools will resolve this error.