[CI] Fix mamba 1.x examples · conda-incubator/setup-miniconda@1a1de20

The process '/Users/runner/miniconda3/condabin/conda' failed with exit code 1

The 'defaults' channel might have been added implicitly. If this is intentional, add 'defaults' to the 'channels' list. Otherwise, consider setting 'conda-remove-defaults' to 'true'.

SpecNotFound: /Users/runner/work/setup-miniconda/setup-miniconda/etc/setup-miniconda-patched-example-empty-channels-environment.yml is not a valid yaml file.