Do not cache files that were part of a batch that had errors when formatting

[brianmcgee]

Recent changes on main removed this logic:

// Append to batch and process if we have enough.
// We do not cache any files that were part of a pipeline in which one or more formatters failed.
// This is to ensure those files are re-processed in later invocations after the user has potentially
// resolved the issue, e.g. fixed a config problem.
if len(task.Errors) == 0 {
	batch = append(batch, task)
	if len(batch) == BatchSize {
		if err := processBatch(); err != nil {
			return err
		}
	}
}