Update Composer, update everything

web/core/modules/locale/locale.post_update.php

@@ -0,0 +1,13 @@
+<?php
+
+/**
+ * @file
+ * Post-update functions for Locale module.
+ */
+
+/**
+ * Clear cache to ensure plural translations are removed from it.
+ */
+function locale_post_update_clear_cache_for_old_translations() {
+  // Remove cache of translations, like '@count[2] words'.
+}