ci: retry registry push on transient timeout

.gitea/workflows/ci.yml

@@ -73,8 +73,17 @@ jobs:
         run: |
           echo "${{ secrets.CI_TOKEN }}" | docker login 10.66.15.22:3000 -u "${{ github.repository_owner }}" --password-stdin
           docker build -t "$IMAGE:${{ steps.tag.outputs.sha }}" -t "$IMAGE:latest" .
-          docker push "$IMAGE:${{ steps.tag.outputs.sha }}"
-          docker push "$IMAGE:latest"
+          # Registry pushes can time out on a slow blob; docker push is resumable, so retry.
+          push_retry() {
+            for i in 1 2 3 4 5; do
+              docker push "$1" && return 0
+              echo "push of $1 failed (attempt $i), retrying in 10s..."
+              sleep 10
+            done
+            return 1
+          }
+          push_retry "$IMAGE:${{ steps.tag.outputs.sha }}"
+          push_retry "$IMAGE:latest"
 
       - name: Bump k8s image tag and commit back
         run: |