ref(replay): Use Date.now() instead of new Date().getTime()

[mydea]

This is slightly shorter and should actually be slightly more performant.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	20.46 KB (-0.14% 🔽)
@sentry/browser - ES5 CDN Bundle (minified)	63.38 KB (-0.18% 🔽)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	19.07 KB (+0.08% 🔺)
@sentry/browser - ES6 CDN Bundle (minified)	56.43 KB (+0.07% 🔺)
@sentry/browser - Webpack (gzipped + minified)	20.72 KB (+0.09% 🔺)
@sentry/browser - Webpack (minified)	67.65 KB (+0.06% 🔺)
@sentry/react - Webpack (gzipped + minified)	20.74 KB (+0.09% 🔺)
@sentry/nextjs Client - Webpack (gzipped + minified)	52.2 KB (+0.02% 🔺)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	33.72 KB (-0.13% 🔽)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	26.1 KB (+0.05% 🔺)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	43.86 KB (-0.03% 🔽)
@sentry/replay - Webpack (gzipped + minified)	37.94 KB (-0.03% 🔽)
@sentry/browser + @sentry/tracing + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	62.06 KB (-0.01% 🔽)
@sentry/browser + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	55.12 KB (0%)