Shift Conda channels from Dockerfile to environment.yml

[erikr]

This PR shifts Conda channels from Dockerfile to environment.yml.

This enables building the Conda environment outside of Docker.

[prihoda]

One more thing that we'll need to fix is #8 but we can do that in a separate PR

[prihoda]

Thanks @erikr, I merged to main branch. We can skip bumping up the release version because the change does not impact the conda release.