Pin google actions versions and upgrade to v3

Author: egrimstad

.github/workflows/publish.yml

@@ -29,11 +29,11 @@ jobs:
           echo "GHA_DOCS_PUBLISH_PROJECT=${GITHUB_REPOSITORY#*/}" >> $GITHUB_ENV
       - uses: actions/checkout@v6
       - id: auth
-        uses: google-github-actions/auth@v2
+        uses: google-github-actions/auth@7c6bc770dae815cd3e89ee6cdf493a5fab2cc093 # v3.0.0
         with:
           credentials_json: "${{ secrets.ENTUR_DOCS_SA }}"
       - name: "Set up Cloud SDK"
-        uses: google-github-actions/setup-gcloud@v2
+        uses: google-github-actions/setup-gcloud@aa5489c8933f4cc7a4f7d45035b3b1440c9c10db # v3.0.1
         # with:
         # version: ">= 363.0.0"
       - name: Upload docs to Entur Docs GCS