Revert "Exercise: method and traits: change output"

[Alx-Lai]

Reverts #2383

Since #2397 is merged, to align the goal in #2478, rollback this temp workaround.

[mgeisler]

Oh, this fails because of an unrelated timeout:

[0-1] Error in "Playground.executes the hello world code and prints the hello message"
Error: Expect  to have text

Expected: StringContaining "🌍"
Received: "The operation timed out: deadline has elapsed"
    at Context.<anonymous> (/home/runner/work/comprehensive-rust/comprehensive-rust/tests/src/playground.test.ts:[30](https://github.com/google/comprehensive-rust/actions/runs/12767680980/job/35586546795?pr=2548#step:15:31):37)
[0-1] Error in "Playground.shows error messages in stderr if the code is broken"
Error: Expect $(`code.result.stderr`) to be displayed

The new JS test is from #2513 (cc @michael-kerscher). We might need to disable it for now if it turns out to be flaky.

[mgeisler]

Thanks a lot for remembering this!

[mgeisler]

Closing and reopening the PR is an easy way to re-trigger the tests. The unrelated failure should be fixed by #2551.