node.go: Add allow-dedupe-failure flag
This makes it possible to temporarily tolerate npm dedupe failures.
npm dedupe can apparently crash due to conflicting package versions;
if this then blocks CI, it’s quite difficult to resolve the problem (you
effectively have to squash all the fixes into a single change, even if
multiple upgrades of unrelated packages are required).
An image built with this flag should still be usable, I believe – it
will just be larger than would be ideal. That said, maybe it would also
be a valid approach to only use this flag to unblock CI, but to stop
deploying new images until npm dedupe works again. We’ll see, I think.
Bug: T329553