Fix a broken link on js-interop page (dart-lang#4687)

Fixed a broken link to the `dart2wasm` instructions.

This fixes dart-lang#4685

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Co-authored-by: Parker Lougheed <parlough@gmail.com>

src/web/js-interop.md

@@ -60,7 +60,7 @@ expected to work across compilers for JS interop.
 * Dart SDK constraint: `>= 2.19`
 * [`package:js`][] constraint: `>= 0.6.6`
 
-[`dart2wasm`]: https://github.com/dart-lang/sdk/blob/main/pkg/dart2wasm/dart2wasm.md#running-dart2wasm
+[`dart2wasm`]: https://github.com/dart-lang/sdk/blob/main/pkg/dart2wasm#running-dart2wasm
 [Dart 3]: https://medium.com/dartlang/dart-3-alpha-f1458fb9d232
 [`package:js`]: {{site.pub-pkg}}/js