Draft: fix: mkdocs i18n plugin now requires new style config

This MR introduces:

• mkdocs i18n plugin now requires new style config (https://github.com/ultrabug/mkdocs-static-i18n/blob/main/config_update_to_v1.py)

relates to https://gitlab.ics.muni.cz/einfra-docs/documentation/-/jobs/1032895

e-infra_theme/partials/i18n_language_switcher.html

@@ -17,16 +17,16 @@
         <button class="md-header__button md-icon" aria-label="Zvolte jazyk">
             <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="m12.87 15.07-2.54-2.51.03-.03A17.52 17.52 0 0 0 14.07 6H17V4h-7V2H8v2H1v2h11.17C11.5 7.92 10.44 9.75 9 11.35 8.07 10.32 7.3 9.19 6.69 8h-2c.73 1.63 1.73 3.17 2.98 4.56l-5.09 5.02L4 19l5-5 3.11 3.11.76-2.04M18.5 10h-2L12 22h2l1.12-3h4.75L21 22h2l-4.5-12m-2.62 7 1.62-4.33L19.12 17h-3.24Z"></path></svg>
             <span>
-                {{ config.plugins.i18n.config.languages[switch_locale].name }}
+                {{ (config.plugins.i18n.config.languages|selectattr("locale", switch_locale)).name }}
             </span>
         </button>
     </a>
     <!-- <div class="md-select__inner">
       <ul class="md-select__list">
-        {% for lang, display in config.plugins.i18n.config.languages.items() -%}
+        {% for lang_config in config.plugins.i18n.config.languages -%}
           <li class="md-select__item">
-            <a href="/{{ lang }}/" hreflang="{{ lang }}" class="md-select__link">
-              {{ display.name }}
+            <a href="/{{ lang_config.locale }}/" hreflang="{{ lang_config.locale }}" class="md-select__link">
+              {{ lang_config.name }}
             </a>
           </li>
           {% endfor %}