use conda

Author: tlambert03

.github/workflows/ci.yaml

@@ -60,12 +60,11 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
           miniforge-version: latest
-          use-mamba: true
           channels: conda-forge,gurobi,defaults
           channel-priority: true
 
       - name: install build deps
-        run: mamba install scip=9.1.0 gurobi=12.0.0 gcovr
+        run: conda install scip=9.1.0 gurobi=12.0.0 gcovr
 
       - name: add gurobi license
         shell: bash