workflow: Skip Python 3.12 tests on Windows for now

Until we've added Python 3.12 to thirdparty packages

.github/workflows/ci.yml

@@ -33,14 +33,17 @@ jobs:
         (cd thirdparty/darwin-libs-a && rm -rf rocket)
 
     - name: Set up Python 3.12
+      if: matrix.os != 'windows-2019'
       uses: actions/setup-python@v4
       with:
         python-version: '3.12'
     - name: Build Python 3.12
+      if: matrix.os != 'windows-2019'
       shell: bash
       run: |
         python makepanda/makepanda.py --git-commit=${{github.sha}} --outputdir=built --everything --no-eigen --python-incdir="$pythonLocation/include" --python-libdir="$pythonLocation/lib" --verbose --threads=4 --windows-sdk=10
     - name: Test Python 3.12
+      if: matrix.os != 'windows-2019'
       shell: bash
       run: |
         python -m pip install pytest