src: always enable idle notifier
This removes the functionality behind
process._startProfilerIdleNotifier()
and
process._stopProfilerIdleNotifier()
and instead always informs V8
over the current event loop state.
The methods themselves are left as noop stubs as per our deprecation policy.
Fixes: https://github.com/nodejs/node/issues/19009
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
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