fix(tracing-internal): Add sideEffects field to package.json

[lforst]

Adds sideEffects: false to the tracing-internal package so that it can be properly tree shaken by Webpack.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	20.66 KB (-0.01% 🔽)
@sentry/browser - ES5 CDN Bundle (minified)	64.52 KB (0%)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	19.2 KB (0%)
@sentry/browser - ES6 CDN Bundle (minified)	56.89 KB (0%)
@sentry/browser - Webpack (gzipped + minified)	20.75 KB (-3.79% 🔽)
@sentry/browser - Webpack (minified)	67.87 KB (-5.89% 🔽)
@sentry/react - Webpack (gzipped + minified)	20.78 KB (-3.79% 🔽)
@sentry/nextjs Client - Webpack (gzipped + minified)	48.6 KB (-6.54% 🔽)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	28.26 KB (+0.01% 🔺)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	26.45 KB (-0.01% 🔽)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	44.78 KB (0%)
@sentry/replay - Webpack (gzipped + minified)	38.86 KB (0%)
@sentry/browser + @sentry/tracing + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	63.5 KB (-0.01% 🔽)
@sentry/browser + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	56.53 KB (-0.01% 🔽)