[llvm] Volunteer myself and Heejin Ahn as WebAssembly backend maintainers (PR #156553)

[Nikita Popov via llvm-commits]

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@@ -312,6 +312,11 @@ marukawa at nec.com (email), [kaz7](https://github.com/kaz7) (GitHub)
 
 #### WebAssembly backend
 
+Derek Schuff \
+dschuff at chromium.org (email), [dschuff](https://github.com/dschuff) (GitHub)
----------------
nikic wrote:

```suggestion
dschuff at chromium.org (email), [dschuff](https://github.com/dschuff) (GitHub) \
```

https://github.com/llvm/llvm-project/pull/156553