Create TensorBoard test classes in all cases (#26005)
Summary:
To give better signal to the user, we will now always create the TensorBoard tests classes and just disable tests if TensorBoard is not installed.
cc lanpa sanekmelnikov natalialunova pietern
[test macos]
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26005
Reviewed By: sanekmelnikov
Differential Revision: D17352430
Pulled By: orionr
fbshipit-source-id: 87a592064f4768ffded76a3d666a8e508a1ef164
