chore: Translate transifex_input.json in pt_PT

99% of minimum 30% reviewed source file: 'transifex_input.json'
on 'pt_PT'.

Sync of partially translated files: 
untranslated content is included with an empty translation 
or source language content depending on file format

Author: transifex-integration[bot]

translations/frontend-app-course-authoring/src/i18n/messages/pt_PT.json

@@ -202,7 +202,7 @@
   "course-authoring.course-optimizer.scanning-step.description": "",
   "course-authoring.course-optimizer.success-step.title": "Sucesso",
   "course-authoring.course-optimizer.success-step.description": "",
-  "course-authoring.course-optimizer.last-scanned-on": "",
+  "course-authoring.course-optimizer.last-scanned-on": "Última verificação em",
   "course-authoring.pages-resources.heading": "Páginas & Recursos",
   "course-authoring.pages-resources.resources.settings.button": "definições",
   "course-authoring.pages-resources.viewLive.button": "Ver ao vivo",