raise exceptions if encountered in threaded concurrency test (#26263)

## Summary & Motivation
Need more traces in debugging spurious sqlite threaded tests.

## How I Tested These Changes
BK

python_modules/dagster/dagster_tests/storage_tests/utils/event_log_storage.py

@@ -5118,20 +5118,16 @@ def _occupy_slot(key: str):
                     time.sleep(0.05)
             storage.free_concurrency_slot_for_step(run_id, key)
 
-        start = time.time()
         with ThreadPoolExecutor() as executor:
-            futures = [executor.submit(_occupy_slot, str(i)) for i in range(100)]
-            while not all(f.done() for f in futures) and time.time() < start + TOTAL_TIMEOUT_TIME:
-                time.sleep(0.1)
-
+            list(
+                executor.map(_occupy_slot, [str(i) for i in range(100)], timeout=TOTAL_TIMEOUT_TIME)
+            )
             foo_info = storage.get_concurrency_info("foo")
             assert foo_info.slot_count == 5
             assert foo_info.active_slot_count == 0
             assert foo_info.pending_step_count == 0
             assert foo_info.assigned_step_count == 0
 
-            assert all(f.done() for f in futures)
-
     def test_zero_concurrency(self, storage: EventLogStorage):
         assert storage
         if not storage.supports_global_concurrency_limits: