[nodejs] Rename dd-trace-js main branch

[BridgeAR]

Motivation

Refs DataDog/dd-trace-js#6551

This should ideally just be approved and I can merge it as soon as I merge the one in dd-trace-js to keep the diverging time window as small as possible.

Changes

Renamed master -> main branch

Workflow

1. ⚠️ Create your PR as draft ⚠️
2. Work on you PR until the CI passes
3. Mark it as ready for review
   • Test logic is modified? -> Get a review from RFC owner.
   • Framework is modified, or non obvious usage of it -> get a review from R&P team

🚀 Once your PR is reviewed and the CI green, you can merge it!

🛟 #apm-shared-testing 🛟

Reviewer checklist

• If PR title starts with [<language>], double-check that only <language> is impacted by the change
• No system-tests internal is modified. Otherwise, I have the approval from R&P team
• A docker base image is modified?
  • the relevant build-XXX-image label is present
• A scenario is added (or removed)?
  • Get a review from R&P team

[cbeauchesne]

There is a master to change in file utils/scripts/load-binary.sh line 315

[BridgeAR]

@cbeauchesne thank you, I had a old checkout. I rebased with latest main and fixed it.