sql: limit max depth of routine execution

We use recursive calls to implement loops in PL/pgSQL, and may in the future allow users to create recursive UDFs. We recently [fixed](https://github.com/cockroachdb/cockroach/pull/155195) a test failure where an infinite loop with tail-call-optimization disabled caused a stack overflow, but that fix is only applied in test builds. While we expect TCO to apply to the recursive structure built for PL/pgSQL loops, it's possible that there are some cases we're missing. We should defensively limit the recursion depth for all routines even for production builds.

Jira issue: CRDB-55345