032: fix missing await on TranslationExecutor.execute_run() in orchestrator_exec

executor.execute_run() is async def but was called without await in
TranslationExecutionEngine.execute_run(). This returned a coroutine
instead of a TranslationRun, causing:
  'coroutine' object has no attribute 'status'
This made every translation run fail in the background execute path.

backend/src/plugins/translate/orchestrator_exec.py

@@ -82,7 +82,7 @@ class TranslationExecutionEngine:
                 on_batch_progress=on_batch_progress,
             )
             try:
-                run = executor.execute_run(run, llm_progress_callback=None, language_stats_map=language_stats_map)
+                run = await executor.execute_run(run, llm_progress_callback=None, language_stats_map=language_stats_map)
             except Exception as e:
                 return _handle_executor_failure(self.db, self.event_log, run, job, e, self.current_user)