That's a feature request on GitHub, see here Copy the .dSYM to the publish directory #15384 Open. You may follow up this feature request and get the latest updates.

The workaround now is to manually copy the .dsym file to the publish directory (bin\Release\net8.0-ios\ios-arm64\publish folder) since the .dsym file has already generated. This GitHub issue may also relate, Is it possible to embed DSYM (folder) in my IPA through Devops build?

For more info, please refer to Publish an iOS app using the command line.