wasmtime: fix lib on darwin

Before:

```
otool -D result-dev/lib/libwasmtime.dylib
result-dev/lib/libwasmtime.dylib:
/private/tmp/nix-build-wasmtime-9.0.2.drv-0/source/target/aarch64-apple-darwin/release/deps/libwasmtime.dylib
```

After:

```
otool -D result-dev/lib/libwasmtime.dylib
result-dev/lib/libwasmtime.dylib:
/nix/store/bz6l7dr60izrq6vga83df9y2p1mgh5hw-wasmtime-9.0.2-dev/lib/libwasmtime.dylib
```

pkgs/development/interpreters/wasmtime/default.nix

@@ -36,6 +36,10 @@ rustPlatform.buildRustPackage rec {
     install -m0644 $src/crates/c-api/include/*.h $dev/include
     install -m0644 $src/crates/c-api/include/wasmtime/*.h $dev/include/wasmtime
     install -m0644 $src/crates/c-api/wasm-c-api/include/* $dev/include
+  '' + lib.optionalString stdenv.isDarwin ''
+    install_name_tool -id \
+      $dev/lib/libwasmtime.dylib \
+      $dev/lib/libwasmtime.dylib
   '';
 
   meta = with lib; {