Restrict breadcrumb JSON generate/parse to depth 5

[sl0thentr0py]

Use max_nesting. Relay already trims this so this data is useless anyway and sometimes causes recursion errors. https://github.com/getsentry/relay/blob/bcbfa7e7db6e4a8f3f0383270fbb2b5cfe668770/relay-event-schema/src/protocol/breadcrumb.rs#L111