Bitcoin Core v0.21.1

`bitcoin-cli walletprocesspsbt` does not trigger a `wallet locked please enter passphrase` warning when using a wallet which holds private keys. To be clear I am experiencing this behavior when using the `default` wallet created by core.

The expected behavior would be to remind the user they are dealing with an encrypted wallet, since `walletprocesspsbt` attempts to access private keys to sign the psbt. It would be useful if a warning were present in the rpc response to remind the user they are dealing with an encrypted wallet. 
RPCResult{RPCResult::Type::NONE, "", ""},
                RPCExamples{
                    HelpExampleCli("keypoolrefill", "")
            + HelpExampleRpc("keypoolrefill", "")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
    std::shared_ptr<CWallet> const pwallet = GetWalletForJSONRPCRequest(request);
    if (!pwallet) return NullUniValue;
    if (pwallet->IsLegacy() && pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Error: Private keys are disabled for this wallet");
    }
    LOCK(pwallet->cs_wallet);
    
    unsigned int kpSize = 0;
    if (!request.params[0].isNull()) {
        if (request.params[0].get_int() < 0)
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, expected valid size.");
        kpSize = (unsigned int)request.params[0].get_int();
    }
    EnsureWalletIsUnlocked(*pwallet);
    pwallet->TopUpKeyPool(kpSize);
    if (pwallet->GetKeyPoolSize() < kpSize) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Error refreshing keypool.");
    }
    return NullUniValue;
},
    };
}
static RPCHelpMan walletpassphrase()