Merge pull request LoopKit#958 from ebouchut/ebouchut/chore/upgrade_github_actions_in_CD_script

Upgrade GitHub Actions in the CD workflow (`publish.yml`)

Author: ebouchut

.github/workflows/publish.yml

@@ -17,10 +17,10 @@ jobs:
       contents: write
     if: github.repository_owner == 'LoopKit'
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@v5
+      - uses: actions/setup-python@v6
         with:
-          python-version: 3.x
+          python-version: ">=3.9"
       - run: pip install -r requirements.txt
       - run: mkdocs build