This is known issue, but interesting that the cause of the crash is different in 3.7-3.8 and 3.9+.

PR 23744 adds recursion checks in the AST validator and optimizer similar to the checks in the symtable. It should not break any existing code because too deep AST tree did not pass checks in the symtable in any case.

But it does not solve all problems. A compound statement with too many "elif"s is still crashed because the new parser uses recursion in C to parse it (elif_stmt_rule). I think it should be a separate issue.