feat: remove write key from payload event when sending it to segment

[rafael-couto-p]

This pull request includes a change to the SegmentDestination function in libs/core-functions/src/functions/segment-destination.ts. The change ensures that the writeKey is removed from the event payload before sending the HTTP request.

• libs/core-functions/src/functions/segment-destination.ts: Added a new constant eventWithoutWriteKey to create a copy of the event with the writeKey set to null and updated the httpRequest payload to use this new constant.

Why?

We are moving away from Segment API and using jitsu to send our events on our website, but we had to create a function to remove the write key that jitsu tries to send to segment, because it's unnecessary and does not work without the function.

Function:

Example of what happens if we don't use that function:

  "status":400
  "statusText":"Bad Request"
  "elapsedMs":273
  "response": {
    "success":false
    "message":"An invalid write key was provided"
    "code":"invalid_request"
  }