feat(core): Deprecate arguments for startSpan()

[mydea]

In v8, there will be a reduced API surface.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser (incl. Tracing, Replay, Feedback) - Webpack (gzipped)	76.49 KB (+0.36% 🔺)
@sentry/browser (incl. Tracing, Replay) - Webpack (gzipped)	67.88 KB (+0.43% 🔺)
@sentry/browser (incl. Tracing, Replay) - Webpack with treeshaking flags (gzipped)	61.5 KB (+0.48% 🔺)
@sentry/browser (incl. Tracing) - Webpack (gzipped)	32.13 KB (+0.9% 🔺)
@sentry/browser (incl. Feedback) - Webpack (gzipped)	30.7 KB (+0.51% 🔺)
@sentry/browser - Webpack (gzipped)	22.07 KB (+0.69% 🔺)
@sentry/browser (incl. Tracing, Replay, Feedback) - ES6 CDN Bundle (gzipped)	74.1 KB (+0.38% 🔺)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (gzipped)	65.75 KB (+0.42% 🔺)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (gzipped)	31.93 KB (+0.88% 🔺)
@sentry/browser - ES6 CDN Bundle (gzipped)	23.76 KB (+0.81% 🔺)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (minified & uncompressed)	206.52 KB (+0.6% 🔺)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (minified & uncompressed)	96.4 KB (+1.28% 🔺)
@sentry/browser - ES6 CDN Bundle (minified & uncompressed)	70.93 KB (+1.31% 🔺)
@sentry/browser (incl. Tracing) - ES5 CDN Bundle (gzipped)	34.89 KB (+0.87% 🔺)
@sentry/react (incl. Tracing, Replay) - Webpack (gzipped)	68.25 KB (+0.43% 🔺)
@sentry/react - Webpack (gzipped)	22.09 KB (+0.65% 🔺)
@sentry/nextjs Client (incl. Tracing, Replay) - Webpack (gzipped)	84.97 KB (+0.33% 🔺)
@sentry/nextjs Client - Webpack (gzipped)	49.33 KB (+0.61% 🔺)
@sentry-internal/feedback - Webpack (gzipped)	16.74 KB (+0.97% 🔺)