Update typescript dependency to v5.9.3 results in test failures in interop_gen_test.dart

Upgrading the NPM dependency to v5.9.3 results in a few failures spots: `parameters` seems to be sometimes null: https://github.com/dart-lang/web/blob/552acc1a87b986eff014b178ba926160a5d2bb8c/web_generator/lib/src/js/typescript.types.dart#L457. https://github.com/dart-lang/web/blob/552acc1a87b986eff014b178ba926160a5d2bb8c/web_generator/lib/src/interop_gen/transform/transformer.dart#L1523 throws because of that. ---- `members` also seems to be sometimes `null`: https://github.com/dart-lang/web/blob/552acc1a87b986eff014b178ba926160a5d2bb8c/web_generator/lib/src/js/typescript.types.dart#L484. https://github.com/dart-lang/web/blob/552acc1a87b986eff014b178ba926160a5d2bb8c/web_generator/lib/src/interop_gen/transform/transformer.dart#L498 throws because of that. There are likely other failure spots after getting past those issues. The first is fixable, but in the second, the type decl seems to point to a function rather than an interface, so it's not obvious what the solution is there. It's also not clear under what situations we should expect a non-nullable vs a nullable. For now, I'll pin the dependency to the current version, v5.8.3. cc @nikeokoronkwo