Bump ext/flecs from c36a9e3 to b7d66a1 (#125)

* Bump ext/flecs from `c36a9e3` to `b7d66a1`

Bumps [ext/flecs](https://github.com/SanderMertens/flecs) from `c36a9e3` to `b7d66a1`.
- [Release notes](https://github.com/SanderMertens/flecs/releases)
- [Commits](SanderMertens/flecs@c36a9e3...b7d66a1)

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

Signed-off-by: dependabot[bot] <support@github.com>

* Update C# bindings

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Co-authored-by: lithiumtoast <lithiumtoast@users.noreply.github.com>