[Translate] Add Brazilian Portuguese [pt_BR]

[melcon]

Add [pt_BR] translation

[github-actions]

• The .po files have been created for pt_BR on the next-release branch.
• They can be found in _translator-files/po/pt_BR/.
• Please consult the README file in _translator-files/ for information on the translation process.

[ignotus666]

I just checked and everything seems to have gone smoothly - your files are on Weblate.

(Note to self: this github-actions message also needs to be updated).

[ignotus666]

Closing as pt_BR has been added successfully.