try to use mamba instead of pure python

.github/workflows/tests.yml

@@ -12,18 +12,19 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - name: Setup Python # Set Python version
-        uses: actions/setup-python@v4
+      - name: Set up mamba
+        uses: conda-incubator/setup-miniconda@v2
         with:
+          activate-environment: test
+          auto-activate-base: false
           python-version: ${{ matrix.python-version }}
-      - name: Install test dependencies
-        run: |
-          # $CONDA is an environment variable pointing to the root of the miniconda directory
-          $CONDA/bin/conda install -y -n base -c conda-forge -c bioconda bcftools
-      # Install pip and pytest
+          miniforge-version: latest
+          miniforge-variant: Mambaforge
+          use-mamba: true
+      - name: Install conda dependencies
+        run: conda install -c conda-forge -c bioconda bcftools pip
       - name: Install pytest and trtools
         run: |
-          python -m pip install --upgrade pip
           pip install pytest pytest-cov trtools
       - name: Test with pytest
         run: |