ref: Remove lastEventId

[lforst]

After the deprecation in v7 we now remove lastEventId.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser (incl. Tracing, Replay, Feedback) - Webpack (gzipped)	78.14 KB (-0.03% 🔽)
@sentry/browser (incl. Tracing, Replay) - Webpack (gzipped)	69.34 KB (-0.04% 🔽)
@sentry/browser (incl. Tracing, Replay with Canvas) - Webpack (gzipped)	73.28 KB (-0.04% 🔽)
@sentry/browser (incl. Tracing, Replay) - Webpack with treeshaking flags (gzipped)	62.99 KB (-0.05% 🔽)
@sentry/browser (incl. Tracing) - Webpack (gzipped)	33.33 KB (-0.09% 🔽)
@sentry/browser (incl. browserTracingIntegration) - Webpack (gzipped)	33.19 KB (-0.09% 🔽)
@sentry/browser (incl. Feedback) - Webpack (gzipped)	31.19 KB (-0.05% 🔽)
@sentry/browser (incl. sendFeedback) - Webpack (gzipped)	31.19 KB (-0.07% 🔽)
@sentry/browser - Webpack (gzipped)	22.45 KB (-0.12% 🔽)
@sentry/browser (incl. Tracing, Replay, Feedback) - ES6 CDN Bundle (gzipped)	76.13 KB (-0.08% 🔽)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (gzipped)	67.66 KB (-0.07% 🔽)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (gzipped)	33.42 KB (-0.17% 🔽)
@sentry/browser - ES6 CDN Bundle (gzipped)	24.51 KB (-0.2% 🔽)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (minified & uncompressed)	213.52 KB (-0.08% 🔽)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (minified & uncompressed)	101.32 KB (-0.16% 🔽)
@sentry/browser - ES6 CDN Bundle (minified & uncompressed)	73.71 KB (-0.21% 🔽)
@sentry/browser (incl. Tracing) - ES5 CDN Bundle (gzipped)	36.58 KB (-0.16% 🔽)
@sentry/react (incl. Tracing, Replay) - Webpack (gzipped)	69.74 KB (-0.04% 🔽)
@sentry/react - Webpack (gzipped)	22.49 KB (-0.14% 🔽)
@sentry/nextjs Client (incl. Tracing, Replay) - Webpack (gzipped)	87.3 KB (-0.03% 🔽)
@sentry/nextjs Client - Webpack (gzipped)	51.49 KB (-0.05% 🔽)
@sentry-internal/feedback - Webpack (gzipped)	17.16 KB (-0.22% 🔽)

[Lms24]

RIP

[AbhiPrasad]

I'm gonna merge this in so that I can take care of merge conflicts with another PR I have