CompactRange stuck on DBImpl::WaitForFlushMemTables when min_write_buffer_number_to_merge > 1

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### Expected behavior
CompactRange() finishes normally when min_write_buffer_number_to_merge > 1

### Actual behavior
CompactRange stuck on DBImpl::WaitForFlushMemTables when min_write_buffer_number_to_merge > 1

### Steps to reproduce the behavior
(1) set min_write_buffer_number_to_merge = 2, max_write_buffer_number = 5;
(2) write some data;
(3) call CompactRange(nullptr, nullptr);

Note that rocksdb version is 8.1.1