fix: revert to Docker Hub for crane pull, make docker load non-blocking

Revert public.ecr.aws ECR mirror back to Docker Hub — the ECR public registry
may not mirror official Docker library images, and an invalid tarball would
block startup since docker load was chained with &&.

Also wrap docker load in (command || true) so a failure doesn't prevent the
GitHub Actions runner from starting. The pre-loaded image is an
optimization, not a hard dependency.

Author: manascb1344

app.py

@@ -225,7 +225,7 @@ def _get_gpu_config(gpu_key: str):
     .run_commands(
         "curl -sL https://github.com/google/go-containerregistry/releases/download/v0.21.5/go-containerregistry_Linux_x86_64.tar.gz | tar -xzf - -C /usr/local/bin crane",  # noqa: E501
         "mkdir -p /images",
-        "crane pull public.ecr.aws/docker/library/node:22-alpine /images/node-22-alpine.tar",
+        "crane pull node:22-alpine /images/node-22-alpine.tar",
     )
     # Layer 2: Python deps (semi-stable)
     .apt_install("python3", "python3-pip", "python-is-python3")
@@ -741,7 +741,7 @@ async def github_webhook(request: Request):
             "bash -c '/start-dockerd.sh &'"
             " && sleep 5"
             " && until docker info > /dev/null 2>&1; do sleep 1; done"
-            " && docker load -i /images/node-22-alpine.tar"
+            " && (docker load -i /images/node-22-alpine.tar || true)"
             " && cd /actions-runner"
             " && export RUNNER_ALLOW_RUNASROOT=1"
             " && export DOCKER_BUILDKIT=1"