ref(node): Add sentry.parent_span_already_sent attribute

[mydea]

This adds a new attribute to spans that we send from the Node SDK because their parent span was already sent. This can be used by us or customers to debug why certain things show up as transactions/root spans in product. We could possibly also use this in the trace view to give users helpful pointers.

[github-actions]

size-limit report 📦

Path	Size	% Change	Change
@sentry/browser	23.81 kB	-	-
@sentry/browser - with treeshaking flags	22.53 kB	-	-
@sentry/browser (incl. Tracing)	39.66 kB	-	-
@sentry/browser (incl. Tracing, Replay)	77.79 kB	-	-
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	67.73 kB	-	-
@sentry/browser (incl. Tracing, Replay with Canvas)	82.49 kB	-	-
@sentry/browser (incl. Tracing, Replay, Feedback)	94.61 kB	-	-
@sentry/browser (incl. Feedback)	40.48 kB	-	-
@sentry/browser (incl. sendFeedback)	28.49 kB	-	-
@sentry/browser (incl. FeedbackAsync)	33.38 kB	-	-
@sentry/react	25.58 kB	-	-
@sentry/react (incl. Tracing)	41.64 kB	-	-
@sentry/vue	28.26 kB	-	-
@sentry/vue (incl. Tracing)	41.46 kB	-	-
@sentry/svelte	23.83 kB	-	-
CDN Bundle	25.36 kB	-	-
CDN Bundle (incl. Tracing)	39.63 kB	-	-
CDN Bundle (incl. Tracing, Replay)	75.57 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback)	81.02 kB	-	-
CDN Bundle - uncompressed	74.08 kB	-	-
CDN Bundle (incl. Tracing) - uncompressed	117.69 kB	-	-
CDN Bundle (incl. Tracing, Replay) - uncompressed	231.61 kB	-	-
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	244.42 kB	-	-
@sentry/nextjs (client)	43.28 kB	-	-
@sentry/sveltekit (client)	40.11 kB	-	-
@sentry/node	167.89 kB	+0.03%	+36 B 🔺
@sentry/node - without tracing	100.62 kB	+0.03%	+30 B 🔺
@sentry/aws-serverless	128.72 kB	+0.03%	+31 B 🔺

View base workflow run

[Lms24]

I'm not 100% happy with the behaviour overall but adding the attribute for diagnosis is a good idea!