Next.js: Upstream removal of "RSC" prefix for navigation transactions

### Description

Next.js spans for navigation rsc requests seem to be prefixed with "RSC" making them look like "RSC GET /post/[id]" which looks funky and is bad for grouping.

Example: https://sentry.sentry.io/performance/trace/e7e80d610bf656ae8a0feaccd0385aa3/?dataset=transactions&eventId=7ed7154f69a64049bc4bd7df44e51445&field=title&field=project&field=user.display&field=timestamp&name=All%20Errors&project=4507657212592128&query=RSC&queryDataset=transaction-like&sort=-timestamp&source=discover&statsPeriod=1h×tamp=1725537009&yAxis=count%28%29

We would like to upstream that the prefix is not there anymore.