Revert "Temporarily revert "build: use `find_package(Python3)` if available"" This reverts commit 35edd704e0fda09e8e634515c0b451d4a8b6b914. Revert the revert and extend the patch further to account for the use of the `PYTHONINTERP_FOUND`. GitOrigin-RevId: 216833b32befd14079130a3b857906f4e301179c