Remove mambaforge for miniforge

Author: roceb

.github/workflows/build.yaml

@@ -22,7 +22,7 @@ jobs:
           python-version: ${{ matrix.pyversion }}
           auto-update-conda: true
           channels: conda-forge,defaults
-          miniforge-variant: Mambaforge
+          miniforge-variant: Miniforge3
           use-mamba: true
           channel-priority: strict
           show-channel-urls: true