test: fix flaky test-inspector-connect-main-thread

Using `console.log()` likely interferes with the functionality of the
test, which also checks the interaction between inspector
and `console.log()` as part of the test. Using `process._rawDebug()`
solves that issue.

Refs: https://github.com/nodejs/node/pull/28870
Refs: https://github.com/nodejs/node/pull/29582

PR-URL: https://github.com/nodejs/node/pull/29588


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>