NOTATIO

Gould says that a hairpin should go to the end of a note's duration, if the intention is to crescendo to the end of the note.
Ending the hairpin before the note would suggest that the last note doesn't get louder.

However, in a lot of traditional engraving, I see hairpins that frequently seem to end at the 'right-hand end' of a notehead.
Precision is important, of course; but I visually dislike the hairpins over-stepping the note.

I believe the hairpin should go as far as it is meant to sound, ie when appropriate it should go to the end of the note.

The second example looks as though it may be from a timpani part (?), in which case what is written is logical.

Bingo on the timp! Well done. I do have lots of other examples, though.

In fact, I'm having trouble finding a hairpin that doesn't behave in this way!

I think David is right and that the correct answer is "it depends".
If that's a timpani part, which would make this valid for any instrument unable to perform a gradual dynamic change over the length of a note, then the hairpin should stop at the right end of the notehead.
On the other hand, if the diminuendo stopped at the right end of the notehead for a string part, I would play the diminuendo to the beginning of the note, and then play the remaining duration at the new lower dynamic. To have a diminuendo that lasts the whole note, I would want to see the hairpin span the whole length of the note, both as a player and as an engraver.

In my contemporary engraving works the composer often splits the duration of long notes to show when the gradual dynamic change starts, a practice that I personally love, and that I find very clear!