Concurrent helm dependency build fail due to race condition

[hanikesn]

We're building and templating a lot of Helm charts in parallel, when some of them share a subchart using symlinks it's possible the build fails due to a race condition: Both build try to download to the same location, one of them finishes first and deletes the file and then the second build crashes as the file is missing:

Error: Error rendering ops/k8s/ingress-nginx-public/Chart.yaml: Error running 'helm dependency build --repository-config /tmp/tmpnb8ufin2.yaml ops/k8s/ingress-nginx-public/charts/ingress-nginx':
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "f6d59f60" chart repository
Update Complete. ⎈Happy Helming!⎈
Saving 1 charts
Downloading ingress-nginx from repo https://kubernetes.github.io/ingress-nginx
Save error occurred:  could not download https://github.com/kubernetes/ingress-nginx/releases/download/helm-chart-4.10.1/ingress-nginx-4.10.1.tgz: open ops/k8s/ingress-nginx-public/charts/ingress-nginx/tmpcharts/ingress-nginx-4.10.1.tgz3661314739: no such file or directory
Error: could not download https://github.com/kubernetes/ingress-nginx/releases/download/helm-chart-4.10.1/ingress-nginx-4.10.1.tgz: open ops/k8s/ingress-nginx-public/charts/ingress-nginx/tmpcharts/ingress-nginx-4.10.1.tgz3661314739: no such file or directory

Output of helm version:

version.BuildInfo{Version:"v3.14.3", GitCommit:"f03cc04caaa8f6d7c3e67cf918929150cf6f3f12", GitTreeState:"clean", GoVersion:"go1.22.1"}