[bitsandfoxes]

Specifically, we want to get to

- Attachments whose stream turns out empty are now dropped instead of being sent empty, e.g. a screenshot that failed to capture ([#5787](https://github.com/getsentry/sentry-dotnet/pull/5787))
- Getting the length of a non-seekable attachment stream no longer throws a first-chance exception ([#5736](https://github.com/getsentry/sentry-dotnet/pull/5736))