fix: check parent exists during instrumentation:

[Asgaroth]

Which problem is this PR solving?

parent can be null depending on how a module was loaded, see:
nodejs/modules#469

Particularly in nextjs a config file is loaded that causes parent to be null and fail the app from building with:

> Build error occurred
TypeError: Cannot read property 'id' of undefined // if (parent.id.includes(`node_modules/${pkg.name}`) || !enabledInstrumentations.has(loadRequest)) {
    at exports.instrumentLoad (/path/node_modules/honeycomb-beeline/lib/instrumentation.js:74:14)
    at Function._load (/path/node_modules/honeycomb-beeline/lib/instrumentation.js:158:16)
    at ModuleWrap.<anonymous> (internal/modules/esm/translators.js:199:29)
    at ModuleJob.run (internal/modules/esm/module_job.js:183:25)
    at async Loader.import (internal/modules/esm/loader.js:178:24) {
  type: 'TypeError'
}

Short description of the changes

• Skip instrumentation if parent is not defined for a module

[MikeGoldsmith]

Looks good, thanks @Asgaroth. I added a test to ensure there isn't a future regression.

[MikeGoldsmith]

Hi @Asgaroth - beeline-nodejs v3.2.1 is now available with your fix 👍🏻

[Asgaroth]

Thanks a lot!