Python 3.12 is system python - that cannot be removed.
$ python --version
Python 3.12.4
It is more likely that you have packages depending on older versions of python.
This will be true if you have content in the folder (the example is from a current Manjaro system)
$ ls /usr/lib/python3.11/site-packages/
ls: cannot access '/usr/lib/python3.11/site-packages/': No such file or directory
And any content in that folder will also hint which packages you need to rebuild.
It is relatively easy to achieve a unterrifying and painless update.
- list all custom package(s)
- remove them
- sync the system
- rebuild custom packatge(s)
To list the custom (foreign) package(s)
pacman -Qqem
To ease the process you way want to pipe the list to a file in your home
pacman -Qqem > ~/my_custom_pkgs.txt
Then feed the list to the package manager to remove the packages
pamac remove $(cat ~/my_custom_pkgs.txt)
Sync your system
sudo pacman -Syu
After successful sync - rebuild the custom package list
pamac build $(cat ~/my_custom_pkgs.txt)
For a more insider knowledge see