gimlet release

Bump gimlet-seq stacksize (#1750)

I'm seeing stack overflow for `gimlet-seq` on the `gimlet-c-dev` image.
Running with a boosted stack size, I see a `stackmargin` size of 1728,
which is above the limit of 1600. Bisecting, this appears to have been
introduced in #1730; I'm guessing it's the nested
`ServerImpl::handle_notifications → VCore::handle_notifications`
dispatch.