Agents were losing authentication during workspace shutdown, causing
shutdown scripts to fail. The auth query required agents to belong to
the latest build, but during shutdown a `stop` build becomes latest while
the `start` build's agents are still running.
Modified the auth query to allow `start` build agents to authenticate
temporarily during `stop` execution. The query allows auth when:
- Agent's `start` build job succeeded
- Latest build is `stop` with `pending`/`running` job status
- Builds are adjacent (`stop` is `build_number + 1`)
- Template versions match
Auth closes once `stop` completes.
Renamed `GetWorkspaceAgentAndLatestBuildByAuthToken` to
`GetAuthenticatedWorkspaceAgentAndBuildByAuthToken` since it returns the
agent's build (not always latest) during shutdown.
Closes coder/internal#1249
Fixes#19467