ci(test.yaml): bump supported python to 3.12 and 3.11

.github/workflows/test.yaml

@@ -16,12 +16,12 @@ jobs:
     strategy:
       matrix:
         os: [ ubuntu-latest, macos-latest, windows-latest ]
-        python-version: ['3.11', '3.10']  # ['3.8', '3.x']
+        python-version: ['3.12', '3.11']  # ['3.8', '3.x']
         exclude:
           # tests with ubuntu-latest, python latest
           # are executed by build_docs.yaml
           - os: ubuntu-latest
-            python-version: 3.11
+            python-version: 3.12
 
     steps:
     - name: Checkout source
@@ -88,7 +88,7 @@ jobs:
         python -m ipykernel install --user --name mfsetup_ci --display-name "mfsetup_ci"
     - name: Install latest PyPI flopy
       shell: bash -l {0}
-      if: ${{ matrix.python-version == 3.10}}
+      if: ${{ matrix.python-version == 3.11}}
       run: pip install flopy --force-reinstall
     - name: Conda list
       shell: bash -l {0}