ref(tracing): Remove sentry_reportAllChanges tag

[AbhiPrasad]

The SDK should avoid setting tags when possible. This PR makes sure we remove this tag, which isn't really useful anymore. We were using this to track metadata when we were tracking improvements to idleTimeout: #4251, but now that we've shipped that with v7, we can remove this tag.

Related: getsentry/team-mobile#60 (comment)

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	19.57 KB (-0.01% 🔽)
@sentry/browser - ES5 CDN Bundle (minified)	60.59 KB (0%)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	18.36 KB (+0.02% 🔺)
@sentry/browser - ES6 CDN Bundle (minified)	54.15 KB (0%)
@sentry/browser - Webpack (gzipped + minified)	20.12 KB (0%)
@sentry/browser - Webpack (minified)	65.75 KB (0%)
@sentry/react - Webpack (gzipped + minified)	20.14 KB (0%)
@sentry/nextjs Client - Webpack (gzipped + minified)	45.97 KB (-0.06% 🔽)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	26.42 KB (-0.13% 🔽)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	24.85 KB (-0.08% 🔽)
@sentry/replay index.js	37.2 KB (0%)
@sentry/replay - Webpack (gzipped + minified)	37.17 KB (0%)
@sentry/replay - Webpack (minified)	124.99 KB (0%)