[nightly] Fix macos nightly conda builds due to miniconda update (#105226)
This is to fix failing macos conda nightly builds: https://github.com/pytorch/pytorch/actions/runs/5551435365/jobs/10147149169
Accompanying builder PR: https://github.com/pytorch/builder/pull/1460
Pull Request resolved: https://github.com/pytorch/pytorch/pull/105226
Approved by: https://github.com/jeanschmidt, https://github.com/malfet
