Do not attach empty sentry-trace and baggage headers

[adinauer]

📜 Description

Do not attach empty sentry-trace and baggage headers if span / transaction is a NoOp

NOTE: Some of the checks could be done earlier too (i.e. before creating the child span) but that would involve more restructuring of the code to still attach breadcrumbs.

💡 Motivation and Context

Fixes #2376

💚 How did you test it?

📝 Checklist

• I reviewed the submitted code
• I added tests to verify the changes
• I updated the docs if needed
• No breaking changes

🔮 Next steps

[github-actions]

	Messages
📖	Do not forget to update Sentry-docs with your feature once the pull request gets approved.

Generated by 🚫 dangerJS against 41586a4

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	431.20 ms	514.86 ms	83.66 ms
Size	1.73 MiB	2.32 MiB	610.45 KiB