Working on "Use std::filesystem. Remove Boost Filesystem & System" #20744, I found an unfortunate [pitfall](https://github.com/bitcoin/bitcoin/pull/20744#issuecomment-946046666) -- `boost/process.hpp` depends on `boost::filesystem` when cross-compiling for Windows. It happens in Guix environment as well.

The goal of this issue is to discuss and find a solution to get rid of `boost::filesystem`.
{
    return m_network == CBaseChainParams::MAIN || m_network_only_args.count(arg) == 0;
}
util::SettingsValue ArgsManager::GetSetting(const std::string& arg) const
{
    LOCK(cs_args);
    return util::GetSetting(
        m_settings, m_network, SettingName(arg), !UseDefaultSection(arg),  false);
}
std::vector<util::SettingsValue> ArgsManager::GetSettingsList(const std::string& arg) const
{
    LOCK(cs_args);
    return util::GetSettingsList(m_settings, m_network, SettingName(arg), !UseDefaultSection(arg));
}
void ArgsManager::logArgsPrefix(