GHA: use micromamba

Author: martinfleis

.github/workflows/tests.yaml

@@ -44,20 +44,17 @@ jobs:
     steps:
       - uses: actions/checkout@v5
 
-      - name: Setup Conda
-        uses: conda-incubator/setup-miniconda@v3
+      - name: Install Conda environment with Micromamba
+        uses: mamba-org/setup-micromamba@v2
         with:
           environment-file: ${{ matrix.env }}
-          miniforge-version: latest
-          miniforge-variant: Miniforge3
-          use-mamba: true
 
       - name: Check and Log Environment
         run: |
           python -V
           python -c "import geopandas; geopandas.show_versions();"
-          conda info
-          conda list
+          micromamba info
+          micromamba list
 
       - name: Test
         run: |