Fix Optional and Union typing hints in ignite/handlers/ema_handler.py

[ramyars466]

Replaces Optional[X] with X | None and Union[X, Y] with X | Y
for modern Python 3.10+ typing style.

Part of #3481

[vfdev-5]

@omkar-334 thanks a lot for reviewing community PRs!
Just a small hint on the review, please ask the contributor to revert all unrelated, extra empty lines etc additions especially in the package itself (it can be fine if in the tests some extra empty line is removed)/

[omkar-334]

@omkar-334 thanks a lot for reviewing community PRs! Just a small hint on the review, please ask the contributor to revert all unrelated, extra empty lines etc additions especially in the package itself (it can be fine if in the tests some extra empty line is removed)/

Yes, i've been looking at extra lines/comments and unrelated lines too, i didn;t tag it here because it was just one. Will take care from next time.
thanks!

[vfdev-5]

Thanks!