Update GitHub Actions checkout to version 6

Author: egonw

.github/workflows/publish_latest_to_zenodo.yml

@@ -12,14 +12,14 @@ jobs:
       ZENODO_TOKEN: ${{ secrets.ZENODO_TOKEN }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           path: wikipathways-data-release
           fetch-depth: 0
           ref: main
 
       - name: Checkout pyzenodo4wpdata
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: wikipathways/pyzenodo4wpdata
           path: pyzenodo4wpdata