Updated transmission.py: extremely minor change to an inaccuracy I found while browsing the repo

[ShuvraneelMitra]

Changed [-1, -1] x [-1, -1] to [-1, 1] x [-1 x 1]

[leftaroundabout]

Thanks for submitting!

In principle this clear-cut fix can easily be merged - but we decided to avoid touching the master branch (except for important bugfixes) until we have finalized the major work on Array-API / PyTorch integration, so as to not make the integration of that diverged branch any more complicated than it already is.

So this PR will have to be rebased on top of those changes. I shall do that when we get there.

[ShuvraneelMitra]

Thanks @leftaroundabout !