Fix build issue with cache

[forsyth2]

Fix build issue with cache, noted in #56 (comment)

[forsyth2]

In 67a9019, I try to update the cache version, as in https://github.com/conda-incubator/setup-miniconda/pull/330/files (which I got to from E3SM-Project/mache#166).

[tomvothecoder]

Note, the publish_docs job won't run until you push (aka merge) to main. The only way to test is to merge this PR or temporarily comment the line below out, then add it back in before merging.

e3sm_data_docs/.github/workflows/build_workflow.yml

Lines 13 to 14 in 2c942ae

	publish-docs:
	if: ${{ github.event_name == 'push' }}

[forsyth2]

Thanks @tomvothecoder. It looks like just the conda cache step works in 49545f3, so I'll try to move ahead with the full rebuild now.

[forsyth2]

Ok, with bc45351, I forced a workflow run and it looks like it updated the official docs -- https://docs.e3sm.org/e3sm_data_docs/_build/html/v2.1/BGC/index.html is accessible now. I'll add back in the if-check and merge.