nit: fix some eventsub mini things (#5895)

lib/twitch-eventsub-ws/include/twitch-eventsub-ws/helpers.hpp

@@ -1,35 +0,0 @@
-#pragma once
-
-#include <boost/json/object.hpp>
-
-#include <iostream>
-#include <optional>
-#include <string_view>
-
-namespace chatterino::eventsub::lib {
-
-template <typename T>
-std::optional<T> readMember(const boost::json::object &obj,
-                            std::string_view key)
-{
-    const auto *it = obj.find(key);
-
-    if (it == obj.end())
-    {
-        // No member with the key found
-        std::cerr << "No member with the key " << key << " found\n";
-        return std::nullopt;
-    }
-
-    const auto result = boost::json::try_value_to<T>(it->value());
-    if (!result.has_value())
-    {
-        std::cerr << key << " could not be deserialized to the desired type\n";
-        // Member could not be serialized to this type
-        return std::nullopt;
-    }
-
-    return result.value();
-}
-
-}  // namespace chatterino::eventsub::lib