As orca should be built against python3.11:

1. meson built against 3.11 should be installed.
   As such a meson package is stored in ../meson, do this as root:
   cd ../meson
   upgradepkg --reinstall *txz
   To revert after having built orca:
   slapt-get -i --reinstall meson

2. Also /usr/bin/python3 should link to /usr/bin/python3.11, so as root type
   cd /usr/bin
   ln -sf python3.11 python3
   Revert to /usr/bin/python3.9 after having built orca. Still as root, type:
   ln -sf python3.9 python3