Clean up FindTBB.cmake warning during build configuration

[jlanz]

When building, this warning appears multiple times during the configuration step:

        CMake Deprecation Warning at cmake_modules/cmake/FindTBB.cmake:47 (cmake_minimum_required):
          Compatibility with CMake < 3.5 will be removed from a future version of
          CMake.

          Update the VERSION argument <min> value or use a ...<max> suffix to tell
          CMake that the project does not need compatibility with older versions.
        Call Stack (most recent call first):
          moonray/hydra/hdMoonray/CMakeLists.txt:47 (find_package)

I’m guessing this can be addressed with a change to our FindTBB.cmake module.

filed from DWA internal issue: MOONRAY-5957

[gripeyes]

Hi @jlanz, sharing these 2 PRs in the case it was related & helped:
#273
#274