GitHub action workflow with conda solver

.github/workflows/python-app.yml

@@ -19,10 +19,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
-    - name: Set up Python 3.8
+    - name: Set up Python 3.11
       uses: actions/setup-python@v4
       with:
-        python-version: '3.8'
+        python-version: '3.11'
     - name: Add conda to system path
       run: |
         # $CONDA is an environment variable pointing to the root of the miniconda directory
@@ -32,13 +32,13 @@ jobs:
         conda env update --file environment-min.yml --name base
     - name: Lint with flake8
       run: |
-        conda install flake8
+        conda install flake8 --solver=classic
         # stop the build if there are Python syntax errors or undefined names
         flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
         # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
         flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
     - name: Test with pytest
       run: |
-        conda install pytest
+        conda install pytest --solver=classic
         cd tests
         pytest