DEPRECATION in TYPO3v12: SiteLanguage->getTwoLetterIsoCode()

[cstrizzolo]

I have checked that the bug exists in the dev-development branch
Yes

I have checked that there are no already open issues or recently closed issues about this bug
Yes

Describe the bug
The following deprecation notice gets added to the deprecation log on TYPO3 v.12.4.8 using vhs v.7.0.1:

Mon, 27 Nov 2023 14:52:50 +0100 [NOTICE] request="e58ca3868b72f" component="TYPO3.CMS.deprecations": Core: Error handler (FE): TYPO3 Deprecation Notice: SiteLanguage->getTwoLetterIsoCode() will be removed in TYPO3 v13.0. Use SiteLanguage->getLocale()->getLanguageCode() instead. in /(...)/typo3_src-12.4.8/typo3/sysext/core/Classes/Site/Entity/SiteLanguage.php line 275

To Reproduce
Although I am not completely sure, I guess this happens when using the following tag in the Fluid templates:

<v:page.languageMenu defaultLanguageLabel="Italian" defaultIsoFlag="it" flagImageType="png" as="menu">

In any case, the deprecated function is used on line 430 in Classes/ViewHelpers/Page/LanguageMenuViewHelper.php:

$result[$language->getLanguageId()] = [
                'label' => $label,
                'iso' => $language->getTwoLetterIsoCode(),
                'flagIdentifier' => $flag
];

Expected behavior
No deprecation notices.