Attempt to deflake DBSSTTest.DestroyDBWithRateLimitedDelete (#9269)

Summary:
This test case seems to be occasionally failing due to the code hitting
the immediate deletion branch in `DeleteScheduler::DeleteFile`. The
patch increases the allowed trash ratio to a huge value to prevent this
from happening.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9269

Test Plan:
```
gtest-parallel --repeat=10000 ./db_sst_test --gtest_filter=DBSSTTest.DestroyDBWithRateLimitedDelete
```

Reviewed By: akankshamahajan15

Differential Revision: D32956596

Pulled By: ltamasi

fbshipit-source-id: 3945e7c1c19ede76698e03c3f133bc1d9fd61b84

db/db_sst_test.cc

@@ -1030,7 +1030,9 @@ TEST_F(DBSSTTest, DestroyDBWithRateLimitedDelete) {
   auto sfm = static_cast<SstFileManagerImpl*>(options.sst_file_manager.get());
 
   sfm->SetDeleteRateBytesPerSecond(1024 * 1024);
-  sfm->delete_scheduler()->SetMaxTrashDBRatio(1.1);
+  // Set an extra high trash ratio to prevent immediate/non-rate limited
+  // deletions
+  sfm->delete_scheduler()->SetMaxTrashDBRatio(1000.0);
   ASSERT_OK(DestroyDB(dbname_, options));
   sfm->WaitForEmptyTrash();
   ASSERT_EQ(bg_delete_file, num_sst_files + num_wal_files);