Add supported Python versions in test matrix

Author: hculea

.github/workflows/validate.yml

@@ -19,15 +19,14 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v3
-
       - name: Set up Python
         uses: actions/setup-python@v4
         with:
-          python-version: '3.x'
-          
+          python-version: ${{ matrix.python-version }}
       - name: Integration Test
         env:
           OP_SERVICE_ACCOUNT_TOKEN: ${{ secrets.TEST_SERVICE_ACCOUNT_TOKEN }}