v1.28.2 - hotfix: 1.28.1 was broken on GPU-less machines

If you installed 1.28.1, upgrade. pip install -U quantprobe

1.28.1's AMD refactor wrapped the non-NVIDIA detection branches in a guard with no else, so a machine with no GPU at all fell through every arm: detect() returned hardware with no vram/vram_bw keys and printed no GPU: line, and None propagated downstream — the same failure mode issue #1 reported. Every CPU-only user of that release was affected; no GPU user could be.

• detect() now always settles vram/vram_bw and always emits exactly one GPU: line. The empty case falls through the same else as every other dead end, which is what the pre-refactor code did.
• The regression test stubs all three probes empty in-process, so the no-GPU path is exercised on GPU machines too — and it was verified against the actual released 1.28.1 file rather than an imitation of the bug: it fails there, passes here.

How it got out. The full suite ran green locally before the release, and this development box has an NVIDIA card, so the broken branch was unreachable here. CI — which runs on GPU-less runners — caught it on four tests within minutes, but the tag and the PyPI upload had already gone out in the same sequence as the push. The rule that follows, and that this release is the first to obey: CI green is a release gate, not a formality that runs after the upload.

None of this is @fboudra's doing — the AMD detection in 1.28.1 is good work and stays exactly as it is. The guard was a merge-time hole that our review and our local suite both missed, and the fix belongs to us.