Bump ext/flecs from f9c7c3d to f3424e4

Bumps [ext/flecs](https://github.com/SanderMertens/flecs) from `f9c7c3d` to `f3424e4`.
- [Release notes](https://github.com/SanderMertens/flecs/releases)
- [Commits](SanderMertens/flecs@f9c7c3d...f3424e4)

---
updated-dependencies:
- dependency-name: ext/flecs
  dependency-type: direct:production
...

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