Reduce dependencies for net 6

[thompson-tomo]

Is your feature request related to a problem? Please describe. I want to minimise dependencies in my project by utilising framework dependencies wherever possible

Describe the solution you'd like System.Text.Json can be provided via the framework ie net 6 as such conditions should be placed on it so that it is only included for net framework. Other dependencies can be optimised.

Describe alternatives you've considered Accept the additional dependency

Additional context n/a

[awright18]

Thanks for your feedback. The engineering team has previously considered this option, and concluded that relying on different dependencies based on the target framework doesn't align with our practices for managing dependencies. However, the next major version of NServiceBus, which will be released soon, does remove this external dependency on System.Text.Json.