Remove `npm update` step from builder notifier scripts

[Krinkle]

There's a trade-off here between automatic updates and consistency/reproducibility with lock files. I think for the long-term, the latter is more favourable given we're not super fast moving. Also, these aren't long-running or public services, so there isn't an inherent benefit to automatic updates from that angle, either.

Source:

infrastructure-puppet/modules/profile/files/builder/builder-do-update.sh

Line 15 in 36c836b

npm update