Someone just vandalized the page. That’s the city’s motto, not its name.

https://europeanribbon.eu/portugal/porto-en/porto-the-noble-and-undefeated-city-of-portugal/

And they even discuss this in the Reddit TIL from last year. https://www.reddit.com/r/todayilearned/comments/1m4cocb/til_that_the_official_name_of_porto_portugal_is/

Exceedingly long names. My most favoured of all things notable and memorable in the linguistic tradition.

These guys have nothing on Krung Thep Maha Nakhon Amon Rattanakosin Mahinthara Ayuthaya Mahadilok Phop Noppharat Ratchathani Burirom Udom Ratchaniwet Maha Sathan Amon Piman Awatan Sathit Sakkathattiya Witsanukam Prasit.