fix(node): Consider tracing error handler for process exit

[timfish]

We attempt to replicate node.js default behaviour of exiting when no error listeners are attached while ignoring Sentry's own listeners.

I noticed that the tracing error handler was not considered.

Magic strings don't feel the ideal way to do this but avoids adding exports to @sentry/core.

[timfish]

Oops, a function name is readonly in strict mode...

[AbhiPrasad]

Oops, a function name is readonly in strict mode

it's always the little things that get you 😭