fix: updated the upgrade job to install appropriate pip version (#26659)

pip version 21 doesn't seem to work well with pip-tools <5.4

.github/workflows/upgrade-python-requirements.yml

@@ -26,6 +26,9 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
 
+      - name: Install pip
+        run: pip install -r requirements/pip.txt
+
       - name: make upgrade
         run: |
           cd $GITHUB_WORKSPACE