fix: no empty requests

[pauldambra]

When processing network requests in the replay network plugin it was possible to emit a request that was

{
   "isInitial": true,
   "requests: ": []
}

that is silly, so let's not do that

[github-actions]

Size Change: -15 B (0%)

Total Size: 849 kB

Filename	Size	Change
dist/recorder-v2.js	106 kB	-15 B (0%)

ℹ️ View Unchanged

Filename	Size
dist/array.full.js	182 kB
dist/array.js	123 kB
dist/es.js	123 kB
dist/exception-autocapture.js	12.1 kB
dist/module.js	123 kB
dist/recorder.js	58.7 kB
dist/surveys-module-previews.js	62.1 kB
dist/surveys.js	58.4 kB

_{compressed-size-action}