test(node): Ensure runner does not create unused tmp files

[mydea]

Noticed locally that I sometimes got unexpected un-removed tmp_xxx dirs in node-integration tests. After some debugging, I figured out the reason: We clean the tmp dir up in afterAll of the test. However, if all tests inside are skipped, afterAll is not executed. So if you run tests in a filtered way - e.g. yarn test -t "xxx" - it would create the tmp dirs, but not delete them.

This PR fixes this by moving the creation of the tmp dir into beforeAll, which equally is not executed when all tests are skipped.

[github-actions]

size-limit report 📦

Path	Size	% Change	Change
@sentry/browser	24.16 kB	added	added
@sentry/browser - with treeshaking flags	22.73 kB	added	added
@sentry/browser (incl. Tracing)	39.87 kB	added	added
@sentry/browser (incl. Tracing, Replay)	77.99 kB	added	added
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags	67.83 kB	added	added
@sentry/browser (incl. Tracing, Replay with Canvas)	82.69 kB	added	added
@sentry/browser (incl. Tracing, Replay, Feedback)	94.79 kB	added	added
@sentry/browser (incl. Feedback)	40.83 kB	added	added
@sentry/browser (incl. sendFeedback)	28.81 kB	added	added
@sentry/browser (incl. FeedbackAsync)	33.7 kB	added	added
@sentry/react	25.88 kB	added	added
@sentry/react (incl. Tracing)	41.86 kB	added	added
@sentry/vue	28.64 kB	added	added
@sentry/vue (incl. Tracing)	41.69 kB	added	added
@sentry/svelte	24.18 kB	added	added
CDN Bundle	25.66 kB	added	added
CDN Bundle (incl. Tracing)	39.76 kB	added	added
CDN Bundle (incl. Tracing, Replay)	75.82 kB	added	added
CDN Bundle (incl. Tracing, Replay, Feedback)	81.27 kB	added	added
CDN Bundle - uncompressed	74.96 kB	added	added
CDN Bundle (incl. Tracing) - uncompressed	117.59 kB	added	added
CDN Bundle (incl. Tracing, Replay) - uncompressed	231.88 kB	added	added
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed	244.48 kB	added	added
@sentry/nextjs (client)	43.89 kB	added	added
@sentry/sveltekit (client)	40.32 kB	added	added
@sentry/node-core	47.99 kB	added	added
@sentry/node	147.02 kB	added	added
@sentry/node - without tracing	92.24 kB	added	added
@sentry/aws-serverless	103.67 kB	added	added

[RulaKhaled]

Thank you!