test(e2e): Disable concurrent tests for canary tests

[lforst]

Due to some concurrency issue in our E2E tests the canary tests are consistently failing. This PR will make the canary tests (hopefully temporarily) non-concurrent so that the canary tests become useful again.

[github-actions]

size-limit report 📦

Path	Size
@sentry/browser - ES5 CDN Bundle (gzipped + minified)	21.12 KB (+0.47% 🔺)
@sentry/browser - ES5 CDN Bundle (minified)	65.86 KB (+0.37% 🔺)
@sentry/browser - ES6 CDN Bundle (gzipped + minified)	19.65 KB (+0.45% 🔺)
@sentry/browser - ES6 CDN Bundle (minified)	58.34 KB (+0.44% 🔺)
@sentry/browser - Webpack (gzipped + minified)	21.28 KB (+0.53% 🔺)
@sentry/browser - Webpack (minified)	69.26 KB (+0.33% 🔺)
@sentry/react - Webpack (gzipped + minified)	21.31 KB (+0.54% 🔺)
@sentry/nextjs Client - Webpack (gzipped + minified)	49.23 KB (+0.25% 🔺)
@sentry/browser + @sentry/tracing - ES5 CDN Bundle (gzipped + minified)	28.74 KB (+0.35% 🔺)
@sentry/browser + @sentry/tracing - ES6 CDN Bundle (gzipped + minified)	26.98 KB (+0.37% 🔺)
@sentry/replay ES6 CDN Bundle (gzipped + minified)	48.6 KB (+2.08% 🔺)
@sentry/replay - Webpack (gzipped + minified)	42.3 KB (+2.03% 🔺)
@sentry/browser + @sentry/tracing + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	67.65 KB (+1.72% 🔺)
@sentry/browser + @sentry/replay - ES6 CDN Bundle (gzipped + minified)	60.57 KB (+2.01% 🔺)