fix(node): Don't leak __span property into breadcrumbs

[lforst]

It seems like the fact that fetch breadcrumbs had the __span property was an accident since like forever. This PR makes it more explicit what we put in the breadcrumb data.

[github-actions]

size-limit report 📦

Path	Size	% Change	Change
@sentry/browser	23.16 KB	+0.13%	+29 B 🔺
@sentry/browser - with treeshaking flags	21.83 KB	+0.12%	+25 B 🔺
@sentry/browser (incl. Tracing)	35.66 KB	+0.14%	+48 B 🔺
@sentry/browser (incl. Tracing, Replay)	72.92 KB	+0.05%	+30 B 🔺
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	63.31 KB	+0.04%	+22 B 🔺
@sentry/browser (incl. Tracing, Replay with Canvas)	77.32 KB	+0.04%	+29 B 🔺
@sentry/browser (incl. Tracing, Replay, Feedback)	89.72 KB	+0.04%	+32 B 🔺
@sentry/browser (incl. Feedback)	39.91 KB	+0.08%	+30 B 🔺
@sentry/browser (incl. sendFeedback)	27.77 KB	+0.1%	+28 B 🔺
@sentry/browser (incl. FeedbackAsync)	32.53 KB	+0.09%	+28 B 🔺
@sentry/react	25.88 KB	+0.09%	+23 B 🔺
@sentry/react (incl. Tracing)	38.52 KB	+0.09%	+33 B 🔺
@sentry/vue	27.38 KB	+0.09%	+24 B 🔺
@sentry/vue (incl. Tracing)	37.52 KB	+0.07%	+24 B 🔺
@sentry/svelte	23.33 KB	+0.11%	+24 B 🔺
CDN Bundle	24.24 KB	+0.11%	+26 B 🔺
CDN Bundle (incl. Tracing)	35.79 KB	+0.07%	+23 B 🔺
CDN Bundle (incl. Tracing, Replay)	70.9 KB	+0.04%	+24 B 🔺
CDN Bundle (incl. Tracing, Replay, Feedback)	76.2 KB	+0.04%	+27 B 🔺
CDN Bundle - uncompressed	71.24 KB	+0.21%	+151 B 🔺
CDN Bundle (incl. Tracing) - uncompressed	106.75 KB	+0.14%	+151 B 🔺
CDN Bundle (incl. Tracing, Replay) - uncompressed	220.82 KB	+0.07%	+151 B 🔺
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	234.02 KB	+0.07%	+151 B 🔺
@sentry/nextjs (client)	38.78 KB	+0.07%	+24 B 🔺
@sentry/sveltekit (client)	36.2 KB	+0.08%	+28 B 🔺
@sentry/node	157.95 KB	-	-
@sentry/node - without tracing	98.84 KB	+0.01%	+2 B 🔺
@sentry/aws-serverless	126.57 KB	-	-

View base workflow run

[codecov]

❌ 1 Tests Failed:

Tests completed	Failed	Passed	Skipped
622	1	621	297

View the top 1 failed tests by shortest run time

middleware.test.ts Should trace outgoing fetch requests inside middleware and create breadcrumbs for it

Stack Traces | 0.087s run time

middleware.test.ts:55:5 Should trace outgoing fetch requests inside middleware and create breadcrumbs for it

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📢 Thoughts on this report? Let us know!

[AbhiPrasad]

There's an argument that this is valuable because it allows people to relate breadcrumbs to spans in a trace.

I'm fine to remove this for now though.