chore(docs): Fix unresolved rebase conflict in Migration.MD

[Lms24]

This PR is a follow up of #5054 which left an unresolved conflict in Migration.MD that emerged while rebasing the PR onto the current 7.x branch.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	18.78 KB (-6.77% 🔽)
@sentry/browser - ES5 CDN Bundle (minified)	58.38 KB (-9.65% 🔽)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	17.54 KB (-6.99% 🔽)
@sentry/browser - ES6 CDN Bundle (minified)	52.61 KB (-9.26% 🔽)
@sentry/browser - Webpack (gzipped + minified)	19.33 KB (-16.83% 🔽)
@sentry/browser - Webpack (minified)	61.47 KB (-24.77% 🔽)
@sentry/react - Webpack (gzipped + minified)	19.35 KB (-16.87% 🔽)
@sentry/nextjs Client - Webpack (gzipped + minified)	42.81 KB (-10.91% 🔽)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	24.43 KB (-6.3% 🔽)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	23 KB (-6.05% 🔽)