[3.12] gh-106905: Use separate structs to track recursion depth in each PyAST_mod2obj call. (GH-113035) (GH-113472)

(cherry picked from commit 48c49739f5502fc7aa82f247ab2e4d7b55bdca62)

Co-authored-by: Yilei Yang <yileiyang@google.com>
Co-authored-by: Gregory P. Smith [Google LLC] <greg@krypto.org>