ref: Remove undefined checks for hub.getScope()

[AbhiPrasad]

In #7551 I made it so that scope was always defined when calling hub.getScope(). This patch refactors some code (mostly tests) to not check if scope is undefined anymore.

We no longer need to do

const span = hub.getScope()?.getSpan();

or

const scope = hub.getScope();
if (scope) {
  scope.addBreadcrumb(...)
}

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	21.3 KB (+0.61% 🔺)
@sentry/browser - ES5 CDN Bundle (minified)	66.43 KB (+0.46% 🔺)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	19.82 KB (+0.59% 🔺)
@sentry/browser - ES6 CDN Bundle (minified)	58.9 KB (+0.53% 🔺)
@sentry/browser - Webpack (gzipped + minified)	21.43 KB (+0.48% 🔺)
@sentry/browser - Webpack (minified)	69.87 KB (+0.51% 🔺)
@sentry/react - Webpack (gzipped + minified)	21.46 KB (+0.45% 🔺)
@sentry/nextjs Client - Webpack (gzipped + minified)	49.38 KB (+0.21% 🔺)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	28.88 KB (+0.33% 🔺)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	27.11 KB (+0.33% 🔺)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	49.34 KB (+0.01% 🔺)
@sentry/replay - Webpack (gzipped + minified)	43.1 KB (+0.07% 🔺)
@sentry/browser + @sentry/tracing + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	68.47 KB (+0.17% 🔺)
@sentry/browser + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	61.38 KB (+0.2% 🔺)