Fix potential stack overflow in PullParserFlex::next_event() recursive call

[coderabbitai]

Issue Description

The next_event() method in stax/src/flex_parser.rs contains a recursive call that could cause stack overflow with deeply nested or malformed JSON input.

Location

• File: stax/src/flex_parser.rs
• Method: PullParserFlex::next_event()
• Issue: Unbounded recursion when no event is produced

Context

This issue was identified during code review and acknowledged to be fixed in a future PR.

References

• Pull Request: Initial implementation #1
• Review Comment: Initial implementation #1 (comment)

Reported by: @kaidokert

[kaidokert]

Recursion is gone now