Remove continue-on-error from NuGet push in publish workflow

The `continue-on-error` option was removed to ensure the workflow fails if the NuGet push step encounters an error. This change improves reliability and ensures issues are caught during the publishing process.

Upgrade .NET version to 8.0.x in GitHub workflows

Updated the .NET version from 7.0.x to 8.0.x in both the CI and publish workflows. This ensures compatibility with the latest .NET features and keeps the project up-to-date. Adjusted configurations to reflect this change while maintaining existing functionality.

Update build script to net7

Set version to '0.3'

Set version to '0.2'