There is no way to properly uninstall 32bit apps on macOS 10.15+ because their un-installers would be 32 bit as well.
The best way would be to perform a clean install of your new Mac by erasing the disk followed by reinstalling macOS. Then when restoring from a backup or migrating from the old system.....only select to restore/migrate your macOS user accounts. Then download & install new current versions of your third party apps. This is the best option since it will get rid of a lot of old junk that is not easily removable otherwise.
You can try to manually remove the applications from the Applications folder, but some of those apps like Office 2008 install lots of items into the lower levels of the OS. With all the new added security of later versions of macOS, it may be impossible to remove some of these low level items from Sonoma. This is why I highly recommend the first option.
I honestly don't know how Migration Assistant handles incompatible items like this. Perhaps another more knowledgeable contributor can chime in to provide more information or better advice or other options.