Add similarity calculation for all pairs of vectors in the unit test …

[milad2073]

…for the circular function

As mentioned in https://github.com/hyperdimensional-computing/torchhd/issues/108#issuecomment-2413286496 the circular test just test the similarity between first vector and other vectors while we have to test the similarity between all pairs of vectors

Description

Added a loop wrapping the previous code and rolling the list of vectors in the end of the loop.

Checklist

• [ ] I added/updated documentation for the changes.
• [ ] I have thoroughly tested the changes.

[mikeheddes]

Thank you @milad2073 for making the unit tests more robust!