fix memory leaks in run-test262

[chqrlie]

No description provided.

[chqrlie]

@saghul: The leaks are gone, but there is a persistent error with the Atomics:

test262/test/built-ins/Atomics/notify/notify-all-on-loc.js:13: strict mode: unexpected error: Test262Error:
The value of reports[NUMAGENT + 1] is "W timeout after Atomics.notify"
Expected SameValue("W timeout before Atomics.notify", "W timeout after Atomics.notify") to be true

[saghul]

Is that new? I didn't see it when I turned them on.

[chqrlie]

The valgrind test is only performed after the merge. You can see the failure(s) in the Actions tab.

[saghul]

Ah the valgring one! Sure thing, I'll take a look!

[saghul]

Looking at all recent runs (https://github.com/quickjs-ng/quickjs/actions/workflows/valgrind.yml) looks like it succeeded at least twice and failed also twice. My first suspicion here is timing, since valgrind is slooooow...