It seems this version string was introduced in a upstream Debian patch indeed, when it was based on a prerelease version of Python 3.9. The patch (git-updates.diff) was dropped later.
Introduced (erroneously): https://salsa.debian.org/cpython-team/python3/-/commit/5334a0144db8e35afa8ae898d0dbd06afa426ccb
Removed: https://salsa.debian.org/cpython-team/python3/-/commit/7952d9ce65aa51d6a23107ce1e30d0d92b1e15c7
Please backport the updated Debian-packaged Python 3.9 to Ubuntu.
It seems this version string was introduced in a upstream Debian patch indeed, when it was based on a prerelease version of Python 3.9. The patch (git-updates.diff) was dropped later.
Introduced (erroneously): /salsa. debian. org/cpython- team/python3/ -/commit/ 5334a0144db8e35 afa8ae898d0dbd0 6afa426ccb
https:/
Removed: /salsa. debian. org/cpython- team/python3/ -/commit/ 7952d9ce65aa51d 6a23107ce1e30d0 d92b1e15c7
https:/
Please backport the updated Debian-packaged Python 3.9 to Ubuntu.