AI behavior, already Month 2 Week 3, a hero enhanced by AI does not have a magic book (0.9.20 5949)

[LeHerosInconnu]

Preliminary checks

• [X] I've checked that there aren't other open issues on the same topic.

Describe the problem requiring a solution

In fheroes2, it's already Month 2 Week 3, and a hero enhanced by AI (Knight) is available in the tavern and it does not have a magic book.

In fheroes2:

https://user-images.githubusercontent.com/43583994/200127381-3ef5bec0-9b35-4451-bf9c-9f448e1ced16.mp4

Here is the save file: Ambrose tavern no book 01.zip

Describe the possible solution

Make the AI buy a magic book for its heroes, at least when they are of a high enough level.

Additional info

Similar remark in this closed issue: https://github.com/ihhub/fheroes2/issues/2158.