Use closest available Unity version to build

[FejZa]

Unity Tools for Azure DevOps - Feature Request

Please describe your feature request

When building a project with the Unity build task, there should be an option to use whatever Unity version is available, that is at least the same major and minor version as the project's Unity version.

Additional context

E.g. when building a project that was last opened with Unity 6000.0.45f1 but the build agent has 6000.0.50f1 installed, it should use 6000.0.50f1, since only the patch version is different.