test: fix test-without-async-context-frame.mjs in debug mode

The test is spawning the python test runner directly without
considering whether the current build is a debug build or not
i.e. does not propage the mode parameter when the test is
run with --mode=debug, so it always ends up using the release
build to run the test even if the test is being run for debug
builds. This patch fixes that.

PR-URL: https://github.com/nodejs/node/pull/57034
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

test/parallel/test-without-async-context-frame.mjs

@@ -49,6 +49,7 @@ describe('without AsyncContextFrame', {
     it(test, async () => {
       const proc = spawn(python, [
         testRunner,
+        `--mode=${process.features.debug ? 'debug' : 'release'}`,
         '--node-args=--no-async-context-frame',
         test,
       ], {