`ManiphestReportController` (which renders `/maniphest/report/burn/`) wastes CPU cycles. Thus remove useless code.
It tries to construct table rows never to be shown: The code calculates rows and adds them via `$table = new AphrontTableView($rows)`, then defines `$panel = new PHUIObjectBoxView()` and does `$panel->setTable($table)` but a bit later `$panel = id(new PhabricatorProjectBurndownChartEngine())` overwrites that table and all its data.
This re-definition of `$panel` was introduced in rP5c1b91ab457db9f3db10d8cc5e07831512645ebb.
The code creates a `PhabricatorProjectBurndownChartEngine` anyway, similar to `PhabricatorProjectReportsController`. So none of those expensive database queries are needed at all. Variables like `list($burn_x, $burn_y) = $this->buildSeries($data);` are never read since rPf8ebc71b8f217ed156f416ddb4cd028dcaa28174.
Bug: T16005