The English Hymnal (1906) has all its Gregorian hymns in square notes. Veni creator is no. 154. Veni sancte Spiritus is no. 156.

Sir Sydney Nicholson's A Plainsong Hymnbook also has these. Sir Sydney's book is a true trove and if one is spotted it should be snatched up. I believe that it is available from Amazon.

English Hymnal almost always uses the Sarum form of chant. Could cause a sensation if that is not the anticipated version. Also, text is NOT underlaid. And, for those who care about such things, the translations are largely antiquarian.

Which text would you like? Original, Urban VIII, or Liber Hymnarius?

This, plus the question of how you want to treat the elisions.

But you could make one for yourself in no time - Benjamin Bloomfield's GABC Transcription Tool makes this a cinch.

Thank you!