Since //web/bubblegum depends on nint, we need to move it to a non user
directory to conform with the policy established via cl/3434.
Note that this likely doesn't mean greater stability (which isn't
really implied in depot anyways), since I still would like to use a more
elaborate calling convention to allow for additional useful features.
Change-Id: I616f905d8df13e3363674aab69a797b0d39fdd79
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3506
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
