update GHA/python-package-conda.yml to use miniforge v3

Author: murrayrm

.github/workflows/python-package-conda.yml

@@ -32,13 +32,12 @@ jobs:
     - uses: actions/checkout@v3
 
     - name: Setup Conda
-      uses: conda-incubator/setup-miniconda@v2
+      uses: conda-incubator/setup-miniconda@v3
       with:
         python-version: ${{ matrix.python-version }}
         activate-environment: test-env
         environment-file: .github/conda-env/test-env.yml
         miniforge-version: latest
-        miniforge-variant: Mambaforge
         channels: conda-forge
         channel-priority: strict
         auto-update-conda: false