Update snok/container-retention-policy action to v3.1.0

Author: renovate[bot]

.github/workflows/build.yml

@@ -125,7 +125,7 @@ jobs:
     permissions:
       packages: write
     steps:
-      - uses: snok/container-retention-policy@v3.0.1
+      - uses: snok/container-retention-policy@v3.1.0
         with:
           account: robojackets
           token: ${{ secrets.GITHUB_TOKEN }}