Excel 2019 or 2021 password cracking

[BigG]

A beginner here on password cracking. So my friend have  a excel file password protected which I am not sure if is 2019 or 2021 office version. He had forgotten the password completely and asked if I could open it somehow. He is ready to buy a new system for it. I see that the latest hashmode on hashcat is only for office 2013 (9600). Does anybody know if it will work for newer excel files? Also if I buy a 4090 GPU, what will be a realistic expectation on cracking the password, say if the password is 8 digits and I need to do a full brute force on it.
I tried Dr.Excel I see Password app on CPU processing, but it was slow. Thanks for your help.

[Snoopy]

first run office2john.py or (exe) from John the Ripper suite on your file and see whether you can extract a hash from the file or not

if not, the used encryption is not (or not yet) supported and therefore not attackable