Troye Sivan

Ariana Grande's highly-anticipated "Thank U, Next" music video has finally dropped ... and it includes an apology to her ex-fiance Pete Davidson. During the "Mean Girls" portion of the video ... Ariana's "Burn Book" includes a page for Pete with the words "Sry I Dipped," "Love U Always" and…

Ariana Grande has been teasing fans and celebs alike to the point of torture with snippets from her "Thank U, Next" music video without a release date ... but now we know when it's gonna drop. Sources close to Ariana tell us the project is set to debut Friday. The music video will highlight 4…