### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current behaviour

The `bitcoind -dbcache=100 -par=4 -disablewallet -reindex-chainstate` command fails with OOM. First reported in https://github.com/bitcoin/bitcoin/issues/28718#issuecomment-1807197107.

### Expected behaviour

RAM usage does not exceed 0.9 GB.

### Steps to reproduce

100% reproducibility with Guix compiled binaries.

### Relevant log output

```
2023-11-17T18:43:31Z [loadblk] UpdateTip: new best=000000000000000016d35e6ca77dea6f4e2caa387f245a712b1df5bbab3c559c height=314541 version=0x00000002 log2_work=80.091273 tx=44112815 date='2014-08-08T11:42:41Z' progress=0.049410 cache=105.6MiB(13710725txo)
```

### How did you obtain Bitcoin Core

Compiled from source

### What version of Bitcoin Core are you using?

master@5aa0c82ccd6ceb4a141686fc8658f679de75a787

### Operating system and version

Armbian 23.8.3 jammy, 1 GB swap-file

### Machine specifications

armv7l, 8 cores, 2 GB RAM
{
        return static_cast<T*>(m_resource->Allocate(n * sizeof(T), alignof(T)));
    }
    /**
     * Forwards each call to the resource.
     */
    void deallocate(T* p, size_t n) noexcept
    {
        m_resource->Deallocate(p, n * sizeof(T), alignof(T));
    }
    ResourceType* resource() const noexcept
    {
        return m_resource;
    }
};
template <class T1, class T2, std::size_t MAX_BLOCK_SIZE_BYTES, std::size_t ALIGN_BYTES>
bool operator==(const PoolAllocator<T1, MAX_BLOCK_SIZE_BYTES, ALIGN_BYTES>& a,
                const PoolAllocator<T2, MAX_BLOCK_SIZE_BYTES, ALIGN_BYTES>& b) noexcept
{
    return a.resource() == b.resource();
}
template <class T1, class T2, std::size_t MAX_BLOCK_SIZE_BYTES, std::size_t ALIGN_BYTES>
bool operator!=(const PoolAllocator<T1, MAX_BLOCK_SIZE_BYTES, ALIGN_BYTES>& a,
                const PoolAllocator<T2, MAX_BLOCK_SIZE_BYTES, ALIGN_BYTES>& b) noexcept
{
    return !(a == b);
}
#endif // BITCOIN_SUPPORT_ALLOCATORS_POOL_H