Bug: Debug the issue where `undefined` is appearing inside the array of segments causing JSON.parse error

[ryan953]

This is the public version of: https://github.com/getsentry/getsentry/issues/8764

Notice that there are undefined segments:

idk where that undefined comes from, the backend wouldn’t emit it because it’s not a keyword in python. The py api isn’t doing any json parsing/serializing, so it’s just passing this on through…
so it might be coming from the sdk, something that’s not calling JSON.stringify but i can’t identify it