How to modify lang attribute in html tag by specific locale

Question

I want to modify this attribute by programmatically
After many times research i found this class in lib magento

Magento\Framework\View\Page\Config

Unfortunately magento team set locale in construct function so i can't use plugin (intercepts) to modify it

public function __construct(
    //Some injection here
) {
   // cut some lines here
   $this->setElementAttribute(
        self::ELEMENT_TYPE_HTML,
        self::HTML_ATTRIBUTE_LANG,
        strstr($this->localeResolver->getLocale(), '_', true)
   );
}

Is there a better way to modify this attribute ?

I have different page html with seperate locale config from backend, and i want to set lang attribute for my own page with selected locale