chore: Delete stale.yml

[hubertdeng123]

This logic for marking issues as stale is now moved to eng-pipes so it's easier to change the logic instead of going through all stale.yml files across Sentry.

https://github.com/getsentry/eng-pipes/blob/3236a12d691c4bf26721b3aad95cc247daad3813/src/webhooks/pubsub/stalebot.ts

[AbhiPrasad]

end of an era 🫡

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	21.95 KB (-0.01% 🔽)
@sentry/browser - ES5 CDN Bundle (minified)	69.13 KB (0%)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	20.28 KB (-0.01% 🔽)
@sentry/browser - ES6 CDN Bundle (minified)	60.38 KB (0%)
@sentry/browser - Webpack (gzipped + minified)	21.9 KB (0%)
@sentry/browser - Webpack (minified)	71.51 KB (0%)
@sentry/react - Webpack (gzipped + minified)	21.92 KB (0%)
@sentry/nextjs Client - Webpack (gzipped + minified)	50.58 KB (+0.03% 🔺)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	30.11 KB (+0.01% 🔺)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	28.16 KB (+0.06% 🔺)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	49.42 KB (0%)
@sentry/replay - Webpack (gzipped + minified)	43.1 KB (0%)
@sentry/browser + @sentry/tracing + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	69.51 KB (+0.02% 🔺)
@sentry/browser + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	61.82 KB (0%)