Don't create spans for Dev Servers requests

[krystofwoldrich]

Description

This is the same issue we have with breadcrumbs.

• Don't add Dev Server and Sentry Dsn request to Breadcrums  #3105

But creating spans for these requests leads to transactions exceeding timeout because there are spans constantly being created.

Also in dev builds with debug on this leads to log spam, which makes it hard to debug the apps.

• Infinite looping on app startup #3205