fix: Remove Debug Simulator if using UTP 2.0+

[simon-lemay-unity]

If UTP 2.0 or later is installed, the debug simulator section still shows up in the Unity Transport component, but is totally non-functional since in that situation the way to do network simulation is through the multiplayer tools package. This caused confusion to at least one user on Discord so here's a PR removing it.

Changelog

• Changed: The Debug Simulator section of the Unity Transport component will now be hidden if Unity Transport 2.0 or later is installed. It was already non-functional in that situation and users should instead use the more featureful Network Simulator tool from the Multiplayer Tools package.

Testing and Documentation

• No tests have been added.
• No documentation changes or additions were necessary.

[unity-cla-assistant]

All committers have signed the CLA.