MNT: instruct users to use conda from Miniforge for it's better licensing.

[nstelter-slac]

Avoid the commercial license of Anaconda and use Miniforge instead, which has fully opensource licence (BSD-3-Clause).

Miniforge is also the listed preferred installer by the conda-forge repository we use anyway.

[nstelter-slac]

i tried out installing miniforge locally, and pydm setup works correctly.

note that it does seem tricky to have both anaconda and miniforge installed at same time (i only had a few local conda envs so i just uninstalled anaconda and removed all my current envs b4 installing miniforge)

[nstelter-slac]

and gh actions already uses miniforge: https://github.com/slaclab/pydm/blob/0806a50857d4de85ec5b88331a7f5b6ee55d9f4a/.github/workflows/run-tests.yml#L35C28-L35C38

[prjemian]

Make sure to replace the `defaults` channel with `nodefaults`. Look for this in any `.condarc` file. User home directory, environment, base, etc.

[nstelter-slac]

Make sure to replace the defaults channel with nodefaults. Look for this in any .condarc file. User home directory, environment, base, etc.

as a note, things workout nicely if u just remove everything anaconda and install miniforge. (although my anaconda only had a few envs i was ok just manually recreating in miniforge and no custom config settings)

the manual uninstall instructions for miniconda instruct u to remove all the .condarc files in your home dir (although not any system wide ones in /etc/ or something): https://www.anaconda.com/docs/getting-started/miniconda/uninstall

and then after doing the default miniforge install, it doesn't seem to create a .condarc with any references to 'defaults', and only has set conda-forge as a channel:

$ conda config --show channels
channels:
  - conda-forge