fix(tracing): Export BrowserTracing directly in CDN bundle

[lobsterkatie]

When we made the changes in #4204 (to export BrowserTracing directly rather than as part of Sentry.Integrations), we didn't make the change in the tracing CDN bundle. While It's true that there's no bundle size issue there (mongo and friends never were getting included in the CDN bundle, so there was nothing to fix), it did mean that when we changed the docs to match the above PR's changes, we ended up breaking CDN folks' usage of BrowserTracing.

This fixes that by making the same change in the tracing CDN bundle as was made for the npm package.

Fixes the problem pointed out in getsentry/sentry-docs#4714.

[github-actions]

size-limit report

Path	Base Size (2a150ee)	Current Size	Change
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	19.65 KB	19.65 KB	+0.01% 🔺
@sentry/browser - ES5 CDN Bundle (minified)	63 KB	63 KB	0%
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	18.32 KB	18.32 KB	+0.01% 🔺
@sentry/browser - ES6 CDN Bundle (minified)	56.15 KB	56.15 KB	0%
@sentry/browser - Webpack (gzipped + minified)	22.1 KB	22.1 KB	0%
@sentry/browser - Webpack (minified)	75.86 KB	75.86 KB	0%
@sentry/react - Webpack (gzipped + minified)	22.14 KB	22.14 KB	0%
@sentry/nextjs Client - Webpack (gzipped + minified)	46.26 KB	46.26 KB	0%
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	27.1 KB	27.1 KB	+0.03% 🔺