feat: Remove tags from spans & transactions

[mydea]

We've refactored all usage away, now we can actually get rid of the tags on the span themselves.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser (incl. Tracing, Replay, Feedback) - Webpack (gzipped)	77.5 KB (-0.08% 🔽)
@sentry/browser (incl. Tracing, Replay) - Webpack (gzipped)	68.75 KB (-0.08% 🔽)
@sentry/browser (incl. Tracing, Replay with Canvas) - Webpack (gzipped)	72.65 KB (-0.08% 🔽)
@sentry/browser (incl. Tracing, Replay) - Webpack with treeshaking flags (gzipped)	62.3 KB (-0.09% 🔽)
@sentry/browser (incl. Tracing) - Webpack (gzipped)	32.98 KB (-0.18% 🔽)
@sentry/browser (incl. browserTracingIntegration) - Webpack (gzipped)	32.98 KB (-0.18% 🔽)
@sentry/browser (incl. Feedback) - Webpack (gzipped)	31.36 KB (-0.01% 🔽)
@sentry/browser (incl. sendFeedback) - Webpack (gzipped)	31.36 KB (-0.02% 🔽)
@sentry/browser - Webpack (gzipped)	22.56 KB (-0.01% 🔽)
@sentry/browser (incl. Tracing, Replay, Feedback) - CDN Bundle (gzipped)	75.59 KB (-0.06% 🔽)
@sentry/browser (incl. Tracing, Replay) - CDN Bundle (gzipped)	67.19 KB (-0.07% 🔽)
@sentry/browser (incl. Tracing) - CDN Bundle (gzipped)	33.05 KB (-0.1% 🔽)
@sentry/browser - CDN Bundle (gzipped)	24.01 KB (-0.02% 🔽)
@sentry/browser (incl. Tracing, Replay) - CDN Bundle (minified & uncompressed)	210.89 KB (-0.07% 🔽)
@sentry/browser (incl. Tracing) - CDN Bundle (minified & uncompressed)	99.69 KB (-0.13% 🔽)
@sentry/browser - CDN Bundle (minified & uncompressed)	71.74 KB (-0.02% 🔽)
@sentry/react (incl. Tracing, Replay) - Webpack (gzipped)	68.99 KB (-0.08% 🔽)
@sentry/react - Webpack (gzipped)	22.6 KB (-0.02% 🔽)
@sentry/nextjs Client (incl. Tracing, Replay) - Webpack (gzipped)	85.47 KB (-0.02% 🔽)
@sentry/nextjs Client - Webpack (gzipped)	49.87 KB (-0.07% 🔽)
@sentry-internal/feedback - Webpack (gzipped)	17.41 KB (-0.02% 🔽)