gh-94947: Disallow parsing walrus with feature_version < (3, 8) (#94948)

* gh-94947: Disallow parsing walrus with feature_version < (3, 8)

* oops, commit the parser

* 📜🤖

 Added by blurb_it.

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>