Merge pull request #1108 from backstage/renovate/actions-setup-python-6.x

Update actions/setup-python action to v6

Author: awanlin

.github/workflows/techdocs.yml

@@ -31,7 +31,7 @@ jobs:
           registry-url: https://registry.npmjs.org/ # Needed for auth
 
       - name: Setup Python 3.9
-        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
+        uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6
         with:
           python-version: '3.13'