YouTube has improved advanced search you can now opt out of showing Shorts videos.

 

YouTube has changed the filters in Advanced Search, stating that it's to improve efficiency and provide the most relevant results to users. Details are as follows:

Type: Added a vertical video category, Shorts. Users can now specify whether to show only Shorts or not (the Videos option currently refers to full-length videos).
Sort By: Changed to Prioritize, reducing the options to Relevance and Popularity (View count remains, but other factors are added to the ranking). Upload date and Rating options have been removed.
Upload date: The "Last hour" option has been removed, with YouTube explaining that it wasn't functioning as desired by users.