Administration - Installation - Core: git checkout release_6 error

/home/ilias/www/html/ilias# git checkout release_6 error:
Ihre lokalen Änderungen in den folgenden Dateien würden beim Auschecken überschrieben werden:
libs/composer/composer.lock
libs/composer/vendor/bin/export-plural-rules
libs/composer/vendor/composer/ClassLoader.php
libs/composer/vendor/composer/autoload_classmap.php
libs/composer/vendor/composer/autoload_files.php
ibs/composer/vendor/composer/autoload_namespaces.php
libs/composer/vendor/composer/autoload_psr4.php
libs/composer/vendor/composer/autoload_real.php
libs/composer/vendor/composer/autoload_static.php
libs/composer/vendor/composer/installed.json
libs/composer/vendor/cweagans/composer-patches/README.md
libs/composer/vendor/cweagans/composer-patches/composer.json
libs/composer/vendor/cweagans/composer-patches/composer.lock         libs/composer/vendor/cweagans/composer-patches/src/Patches.php         libs/composer/vendor/filp/whoops/CHANGELOG.md         libs/composer/vendor/filp/whoops/LICENSE.md         libs/composer/vendor/filp/whoops/composer.json         libs/composer/vendor/filp/whoops/src/Whoops/Exception/Formatter.php         libs/composer/vendor/filp/whoops/src/Whoops/Exception/Frame.php         libs/composer/vendor/filp/whoops/src/Whoops/Exception/FrameCollection.php         libs/composer/vendor/filp/whoops/src/Whoops/Exception/Inspector.php         libs/composer/vendor/filp/whoops/src/Whoops/Handler/JsonResponseHandler.php         libs/composer/vendor/filp/whoops/src/Whoops/Handler/PlainTextHandler.php         libs/composer/vendor/filp/whoops/src/Whoops/Handler/PrettyPageHandler.php         libs/composer/vendor/filp/whoops/src/Whoops/Handler/XmlResponseHandler.php         libs/composer/vendor/filp/whoops/src/Whoops/Resources/css/whoops.base.css         libs/composer/vendor/filp/whoops/src/Whoops/Resources/js/whoops.base.js         libs/composer/vendor/filp/whoops/src/Whoops/Resources/views/env_details.html.php         libs/composer/vendor/filp/whoops/src/Whoops/Resources/views/frame_code.html.php         libs/composer/vendor/filp/whoops/src/Whoops/Resources/views/frame_list.html.php         libs/composer/vendor/filp/whoops/src/Whoops/Resources/views/frames_description.html.php         libs/composer/vendor/filp/whoops/src/Whoops/Resources/views/header.html.php         libs/composer/vendor/filp/whoops/src/Whoops/Resources/views/layout.html.php         libs/composer/vendor/filp/whoops/src/Whoops/Resources/views/panel_left.html.php         libs/composer/vendor/filp/whoops/src/Whoops/Run.php         libs/composer/vendor/filp/whoops/src/Whoops/RunInterface.php         libs/composer/vendor/filp/whoops/src/Whoops/Util/SystemFacade.php         libs/composer/vendor/filp/whoops/src/Whoops/Util/TemplateHelper.php         libs/composer/vendor/gettext/gettext/CONTRIBUTING.md         libs/composer/vendor/gettext/gettext/LICENSE         libs/composer/vendor/gettext/gettext/README.md         libs/composer/vendor/gettext/gettext/composer.json         libs/composer/vendor/gettext/gettext/src/BaseTranslator.php         libs/composer/vendor/gettext/gettext/src/Extractors/Blade.php         libs/composer/vendor/gettext/gettext/src/Extractors/CsvDictionary.php         libs/composer/vendor/gettext/gettext/src/Extractors/Extractor.php         libs/composer/vendor/gettext/gettext/src/Extractors/ExtractorInterface.php         libs/composer/vendor/gettext/gettext/src/Extractors/Jed.php         libs/composer/vendor/gettext/gettext/src/Extractors/JsCode.php         libs/composer/vendor/gettext/gettext/src/Extractors/JsonDictionary.php         libs/composer/vendor/gettext/gettext/src/Extractors/Mo.php         libs/composer/vendor/gettext/gettext/src/Extractors/PhpArray.php         libs/composer/vendor/gettext/gettext/src/Extractors/PhpCode.php         libs/composer/vendor/gettext/gettext/src/Extractors/Po.php         libs/composer/vendor/gettext/gettext/src/Extractors/Twig.php         libs/composer/vendor/gettext/gettext/src/Extractors/YamlDictionary.php         libs/composer/vendor/gettext/gettext/src/Generators/CsvDictionary.php         libs/composer/vendor/gettext/gettext/src/Generators/Generator.php         libs/composer/vendor/gettext/gettext/src/Generators/GeneratorInterface.php         libs/composer/vendor/gettext/gettext/src/Generators/Jed.php         libs/composer/vendor/gettext/gettext/src/Generators/JsonDictionary.php         libs/composer/vendor/gettext/gettext/src/Generators/Mo.php         libs/composer/vendor/gettext/gettext/src/Generators/PhpArray.p
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