Update FindTBB.cmake: fix cmake error for TBB 2021

[cdb0y511]

fix file failed to open for reading (No such file or directory): /usr/include/tbb/tbb_stddef.h inside docker build (TBB 2021.5 has removed the tbb_stddef.h)
related to #769

[varunagrawal]

@cdb0y511 thanks for the contribution.

Your changes are throwing the error

CMake Error at cmake/FindTBB.cmake:186 (file):
  file failed to open for reading (No such file or directory):

    /usr/include/oneapi/tbb/version.h
Call Stack (most recent call first):
  cmake/HandleTBB.cmake:4 (find_package)
  CMakeLists.txt:79 (include)

Could it be that this change is not backwards compatible?

[talregev]

@cdb0y511
For fixing latest TBB, just delete the FindTBB.cmake file. Cmake already have a very good finding TBB for the new and for gtsam versions. I can make a PR for that, or you can try it your own.

[talregev]

@cdb0y511 Like mean that you want me to do it?
I will make a PR, and let me know if it work for you.

[varunagrawal]

Closing as this is superseded by #1567