Only use python3.11 for doctests in CI

.github/workflows/doc-tests.yml

@@ -15,16 +15,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python: ["3.8", "3.12"]
+        python: ["3.11"]
         gurobipy: ["10.0.3", "11.0.2"]
-        scipy: ["1.8.1", "1.13.0"]
-        exclude:
-          - python: "3.12"
-            gurobipy: "10.0.3"
-          - python: "3.8"
-            scipy: "1.13.0"
-          - python: "3.12"
-            scipy: "1.8.1"
 
     steps:
       - uses: actions/checkout@v4
@@ -38,7 +30,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install -rdocs/requirements.txt
-          python -m pip install gurobipy==${{ matrix.gurobipy }} scipy==${{ matrix.scipy }}
+          python -m pip install gurobipy==${{ matrix.gurobipy }}
           python -m pip install .[examples]
       - name: Run doctests
         run: |