fix(ember): Ensure only one client is created & Replay works

[mydea]

This uses the new addIntegration API to add browser tracing, which means we do not need to call Sentry.init() twice, which lead to issues as replay relies on the client remaining consistent.

Fixes#7640

[Lms24]

I have no idea about Ember-specifics but the change makes sense to me.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	20.77 KB (-0.01% 🔽)
@sentry/browser - ES5 CDN Bundle (minified)	64.88 KB (0%)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	19.28 KB (0%)
@sentry/browser - ES6 CDN Bundle (minified)	57.2 KB (0%)
@sentry/browser - Webpack (gzipped + minified)	20.83 KB (0%)
@sentry/browser - Webpack (minified)	68.17 KB (0%)
@sentry/react - Webpack (gzipped + minified)	20.86 KB (0%)
@sentry/nextjs Client - Webpack (gzipped + minified)	48.68 KB (0%)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	28.36 KB (0%)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	26.53 KB (0%)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	44.87 KB (0%)
@sentry/replay - Webpack (gzipped + minified)	38.86 KB (0%)
@sentry/browser + @sentry/tracing + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	63.58 KB (-0.01% 🔽)
@sentry/browser + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	56.62 KB (0%)