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.

if (!gArgs.GetArg("-changetype", "").empty()) {
        OutputType out_type;
        if (!ParseOutputType(gArgs.GetArg("-changetype", ""), out_type)) {
            error = strprintf(_("Unknown change type '%s'"), gArgs.GetArg("-changetype", ""));
            return nuptr;
        }
        waetInstance->m_default_change_type = out_type;
    }
    if (gArgs.IsArgSet("-mintxfee")) {
        CAmount n = 0;
        if (!ParseMoney(gArgs.GetArg("-mintxfee", ""), n) || 0 == n) {
            error = AmountErrMsg("mintxfee", gArgs.GetArg("-mintxfee", ""));
            return nuptr;
        }
        if (n > HIGH_TX_FEE_PER_KB) {
            warnings.push_back(AmountHighWarn("-mintxfee") + Untranslated(" ") +
                               _("This is the minimum transaction fee you pay on every transaction."));
        }
        waetInstance->m_min_fee = CFeeRate(n);
    }
    if (gArgs.IsArgSet("-maxapsfee")) {
        const std::string max_aps_fee{gArgs.GetArg("-maxapsfee", "")};
        CAmount n = 0;
        if (max_aps_fee == "-1") {
            n = -1;
        } else if (!ParseMoney(max_aps_fee, n)) {
            error = AmountErrMsg("maxapsfee", max_aps_fee);
            return nuptr;
        }
        if (n > HIGH_APS_FEE) {