fix(replay): Ensure we do not flush if flush took too long

[mydea]

Add another safeguard to avoid too-long replays, in the case where flushing takes too long.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser (incl. Tracing, Replay) - Webpack (gzipped)	75.06 KB (+0.28% 🔺)
@sentry/browser (incl. Tracing) - Webpack (gzipped)	31.11 KB (0%)
@sentry/browser - Webpack (gzipped)	21.81 KB (0%)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (gzipped)	69.66 KB (+0.18% 🔺)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (gzipped)	28.16 KB (+0.04% 🔺)
@sentry/browser - ES6 CDN Bundle (gzipped)	20.18 KB (+0.05% 🔺)
@sentry/browser (incl. Tracing, Replay) - ES6 CDN Bundle (minified & uncompressed)	219.64 KB (+0.27% 🔺)
@sentry/browser (incl. Tracing) - ES6 CDN Bundle (minified & uncompressed)	84.69 KB (+0.03% 🔺)
@sentry/browser - ES6 CDN Bundle (minified & uncompressed)	59.86 KB (+0.04% 🔺)
@sentry/browser (incl. Tracing) - ES5 CDN Bundle (gzipped)	31.03 KB (+0.04% 🔺)
@sentry/react (incl. Tracing, Replay) - Webpack (gzipped)	65.26 KB (+0.33% 🔺)
@sentry/react - Webpack (gzipped)	21.84 KB (0%)
@sentry/nextjs Client (incl. Tracing, Replay) - Webpack (gzipped)	92.88 KB (+0.26% 🔺)
@sentry/nextjs Client - Webpack (gzipped)	50.64 KB (+0.06% 🔺)