Update conda_index command in os-blas-test-matrix workflow by murrayrm · Pull Request #981

Update conda_index command in os-blas-test-matrix workflow by murrayrm · Pull Request #981 · python-control/python-control

This PR updates the code used for the os-blas-test-matrix GitHub Actions workflow to reflect changes in the way conda index is implemented: https://conda.github.io/conda-index/.

This does not affect users, so I will merge this somewhat quick (w/ or w/out review -:). Need it to run the full OS/BLAS test matrix before release 0.10.0.