MAINTAINERS: add HFS/HFS+ maintainers

MAINTAINERS: add HFS/HFS+ maintainers

Both the hfs and hfsplus filesystem have been orphaned since at least
2014, i.e., over 10 years. However, HFS/HFS+ driver needs to stay
for Debian Ports as otherwise we won't be able to boot PowerMacs
using GRUB because GRUB won't be usable anymore on PowerMacs with
HFS/HFS+ being removed from the kernel.

This patch proposes to add Viacheslav Dubeyko and
John Paul Adrian Glaubitz as maintainers of HFS/HFS+ driver.

Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Link: https://lore.kernel.org/20250417223507.1097186-1-slava@dubeyko.com
Signed-off-by: Christian Brauner <brauner@kernel.org>