## Description
This PR updates the lifecycle executor to explicitly exclude prebuilt
workspaces from being considered for lifecycle operations such as
`autostart`, `autostop`, `dormancy`, `default TTL` and `failure TTL`.
Prebuilt workspaces (i.e., those owned by the prebuild system user) are
handled separately by the prebuild reconciliation loop. Including them
in the lifecycle executor could lead to unintended behavior such as
incorrect scheduling or state transitions.
## Changes
* Updated the lifecycle executor query
`GetWorkspacesEligibleForTransition` to exclude workspaces with
`owner_id = 'c42fdf75-3097-471c-8c33-fb52454d81c0'` (prebuilds).
* Added tests to verify prebuilt workspaces are not considered in:
* Autostop
* Autostart
* Default TTL
* Dormancy
* Failure TTL
Fixes: https://github.com/coder/coder/issues/18740
Related to: https://github.com/coder/coder/issues/18658
Relates to https://github.com/coder/coder/issues/15082
Further to https://github.com/coder/coder/pull/15429, this reduces the
amount of false-positives returned by the 'is eligible for autostart'
part of the query. We achieve this by calculating the 'next start at'
time of the workspace, storing it in the database, and using it in our
`GetWorkspacesEligibleForTransition` query.
The prior implementation of the 'is eligible for autostart' query would
return _all_ workspaces that at some point in the future _might_ be
eligible for autostart. This now ensures we only return workspaces that
_should_ be eligible for autostart.
We also now pass `currentTick` instead of `t` to the
`GetWorkspacesEligibleForTransition` query as otherwise we'll have one
round of workspaces that are skipped by `isEligibleForTransition` due to
`currentTick` being a truncated version of `t`.
When starting a workspace, if the deadline crosses an autostart boundary, the deadline is set to autostart + TTL.
This copies the behavior in `ActivityBumpWorkspace`, but does not require activity.
Susana Ferreira