chore(ci): aggressively prune buildkit caches inside host builder containers

.gitea/workflows/deploy.yml

@@ -59,6 +59,11 @@ jobs:
           docker ps --format "table {{.Names}}\t{{.Status}}\t{{.Image}}" || true
           echo "=== Host Docker Info ==="
           docker info || true
+          echo "Pruning host Buildkit builder caches aggressively..."
+          for container in $(docker ps --filter "name=buildx_buildkit_builder" --format "{{.Names}}"); do
+            echo "Pruning Buildkit inside container: $container"
+            docker exec -i "$container" buildctl prune --all || true
+          done
           echo "Purging old build layers, unused volumes and images..."
           docker builder prune -a -f || true
           docker volume prune -f || true