Simplify conda environment.yml file

As originally posted here:

I recommend not using the output of conda export, but rather creating a simpler, more portable file that includes only those packages that xpipeline needs (and not, for example, the dependencies of your dependencies), with loose (but valid) version specs, e.g:

channels:
  - conda-forge
dependencies:
  - c-compiler
  - fftw
  - framel-matlab
  - gsl
  - pkg-config
  - python >=3.10

@patrick-sutton, are you able to make that change?