MNT: Use CTK 12.9.1 to build `cuda-bindings` 12.9.x

[leofang]

Need to update this line:

cuda-python/ci/versions.json

Line 4 in d1a166a

"version": "12.9.0"

[leofang]

After updating this line, we should also ensure that during the test stage we always install local CTK 12.9.1. This is to avoid blowing up the limited GitHub Cache space (10GB only). We don't want to cache both 12.9.0 and 12.9.1.

[leofang]

Closed by #955 & #960. (I wonder why GitHub did not auto-close this issue? 🤔)