[Chapel Merge] Update the GPU technote for 2.7

Branch: refs/heads/main
Revision: a95dd8e4a13b817c9f773207ed03211b652cb248
Author: e-kayrakli
Link: Update the GPU technote for 2.7 by e-kayrakli · Pull Request #28196 · chapel-lang/chapel · GitHub
Log Message:
Update the GPU technote for 2.7 (#28196)

Adds a note about CUDA 12.9, and updates systems on which we test GPU
support.

[Reviewed by @jabraham17]

Compare: Comparing 609fe2e4c9baefe172b31826bbc6134cbec2d53b...1a06ada2f52f5df2c8045e4473519cf8aa040b87 · chapel-lang/chapel · GitHub

Diff:
M doc/rst/technotes/gpu.rst
https://github.com/chapel-lang/chapel/pull/28196.diff