[AUTO-CHERRYPICK] Updated PR checks to use Python 3.9. - branch main (#11798)

Co-authored-by: Pawel Winogrodzki <pawelwi@microsoft.com>

.github/workflows/check-entangled-specs.yml

@@ -25,10 +25,10 @@ jobs:
         uses: actions/checkout@v4
 
       # For consistency, we use the same major/minor version of Python that CBL-Mariner ships
-      - name: Setup Python 3.7
+      - name: Setup Python 3.9
         uses: actions/setup-python@v4
         with:
-          python-version: 3.7
+          python-version: 3.9
 
       - name: Get Python dependencies
         run: python3 -m pip install -r toolkit/scripts/requirements.txt

.github/workflows/lint-specs.yml

@@ -62,10 +62,10 @@ jobs:
           path: 'spec-cleaner'
 
       # For consistency, we use the same major/minor version of Python that CBL-Mariner ships
-      - name: Setup Python 3.7
+      - name: Setup Python 3.9
         uses: actions/setup-python@v4
         with:
-          python-version: 3.7
+          python-version: 3.9
 
       # We take our version of the linting tool from the master branch to ensure rules
       # are consistent across all branches