Remove duplicate dependency lists in conda environment YAML files

[mfisher87]

We could:

• Remove them. Personally, I don't think this pure python project has a reason to include them. We can advise conda users to use conda to create the environment, but use pip to install into it.
• Replace them with environment specification files that don't duplicate the dependency lists:

  name: earthaccess
  channels:
    - conda-forge
    - nodefaults
  dependencies:
    - python>=3.9
    - pip
    - pip:
        - --editable .[dev]