The `dumpwallet` RPC command throws an error at the signet node and stops it.
~~This does not happen in mainnet or testnet, where the command worked successfully in my tests..~~
Originally this error was only happening on signet, but it also happened on testnet after it worked successfully for a while.

**Expected behavior**

The RPC `dumpwallet` command is expected to return a success message and create the dump file that contains the private keys.

**Actual behavior**

The command returns an error on client side (`bitcoin-cli`):
`error: timeout on transient error: Could not connect to the server 127.0.0.1:38332 (error code 1 - "EOF reached")
Make sure the bitcoind server is running and that you are connecting to the correct RPC port.`

And it throws an error at the signet node and stops it.

```
POTENTIAL DEADLOCK DETECTED
Previous lock order was:
  'cs_wallet' in wallet/wallet.cpp:2860 (in thread 'httpworker.1')
  (2) '::cs_main' in node/interfaces.cpp:687 (in thread 'httpworker.1')
  'm_node.mempool->cs' in node/interfaces.cpp:687 (in thread 'httpworker.1')
  'cs_wallet' in wallet/wallet.cpp:1204 (in thread 'httpworker.1')
  (1) 'cs_KeyStore' in script/signingprovider.cpp:165 (in thread 'httpworker.1')
Current lock order is:
  'wallet.cs_wallet' in wallet/rpcdump.cpp:743 (in thread 'httpworker.3')
  (1) 'spk_man.cs_KeyStore' in wallet/rpcdump.cpp:743 (in thread 'httpworker.3')
  (1) 'spk_man->cs_KeyStore' in wallet/wallet.cpp:2303 (in thread 'httpworker.3')
  (2) 'cs_main' in node/interfaces.cpp:493 (in thread 'httpworker.3')
Assertion failed: detected inconsistent lock order for 'cs_main' in node/interfaces.cpp:493 (in thread 'httpworker.3'), details in debug log.
Aborted (core dumped)
```

**To reproduce**

Start the node on signet mode:
`bitcoind -signet`

And dump an existing wallet:
`bitcoin-cli -signet -rpcwallet="legacy_wallet_01" dumpwallet "filename"`

**System information**

The bitcoin node was compiled from master (commit: `df2b5dadfb2dc21b05e5a60b71987fb5b96201f5`)
Ubuntu 20.04, 8 CPUs, 12 GiB RAM and SSD.

"block from time %d, which is after or within %d seconds of key creation, and "
                                      "could contain transactions pertaining to the key. As a result, transactions "
                                      "and coins using this key may not appear in the wallet. This error could be "
                                      "caused by pruning or data corruption (see bitcoind log for details) and could "
                                      "be dealt with by downloading and rescanning the relevant blocks (see -reindex "
                                      "and -rescan options).",
                                GetImportTimestamp(request, now), scannedTime - TIMESTAMP_WINDOW - 1, TIMESTAMP_WINDOW)));
                    response.push_back(std::move(result));
                }
                ++i;
            }
        }
    }
    return response;
},
    };
}
static UniValue ProcessDescriptorImport(CWallet& wallet, const UniValue& data, const int64_t timestamp) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet)
{
    UniValue warnings(UniValue::VARR);
    UniValue result(UniValue::VOBJ);
    try {
        if (!data.exists("desc")) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Descriptor not found.");
        }
        const std::string& descriptor = data["desc"].get_str();
        const bool active = data.exists("active") ? data["active"].get_bool() : false;
        const bool internal = data.exists("internal") ? data["internal"].get_bool() : false;
        const std::string& label = data.exists("label") ? data["label"].get_str() : "";
        //