The provisioner state for a workspace build was being loaded for every
long-lived agent rpc connection. Since this state can be anywhere from
kilobytes to megabytes this can gradually cause the `coderd` memory
footprint to grow over time. It's also a lot of unnecessary allocations
for every query that fetches a workspace build since only a few callers
ever actually reference the provisioner state.
This PR removes it from the returned workspace build and adds a query to
fetch the provisioner state explicitly.
The experimental functions in `golang.org/x/exp/slices` are now
available in the standard library since Go 1.21.
Reference: https://go.dev/doc/go1.21#slices
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
Joins in fields like `username`, `avatar_url`, `organization_name`,
`template_name` to `workspaces` via a **view**.
The view must be maintained moving forward, but this prevents needing to
add RBAC permissions to fetch related workspace fields.