The RPC docs are now enforced to specify the json type of the args and results at compile time. However, some help texts contain the type twice. (E.g. https://github.com/bitcoin/bitcoin/pull/17809#discussion_r386295217 ). The duplicate type in the description should be removed.

Duplicates can be found with this command:

```sh
git grep --extended-regexp  'RPC.*(ARR|OBJ).*json (array|object)' src/rpc/ src/wallet/rpc*
```

#### Useful skills:

Basic understanding of how to compile and run Bitcoin Core.

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const int num_blocks{request.params[0].get_int()};
    const int64_t max_tries{request.params[2].isNull() ? 1000000 : request.params[2].get_int()};
    FlatSigningProvider key_provider;
    std::string error;
    const auto desc = Parse(request.params[1].get_str(), key_provider, error,  false);
    if (!desc) {
        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, error);
    }
    if (desc->IsRange()) {
        throw JSONRPCError(RPC_INVALID_PARAMETER, "Ranged descriptor not accepted. Maybe pass through deriveaddresses first?");
    }
    FlatSigningProvider provider;
    std::vector<CScript> coinbase_script;
    if (!desc->Expand(0, key_provider, coinbase_script, provider)) {
        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Cannot derive script without private keys"));
    }
    const CTxMemPool& mempool = EnsureMemPool();
    CHECK_NONFATAL(coinbase_script.size() == 1);
    return generateBlocks(mempool, coinbase_script.at(0), num_blocks, max_tries);
}
static UniValue generatetoaddress(const JSONRPCRequest& request)
{
            RPCHelpMan{"generatetoaddress",
                "\nMine blocks immediately to a specified address (before the RPC call returns)\n",
                {
                    {"nblocks", RPCArg::Type::NUM, RPCArg::Optional::NO, "How many blocks are generated immediately."},
                    {"address", RPCArg::Type::STR, RPCArg::Optional::NO, "The address to send the newly generated bitcoin to."},
                    {"maxtries", RPCArg::Type::NUM,  "1000000", "How many iterations to try."},
                },
                RPCResult{