Say out loud that Windows on ARM gets an emulated whisper

Checked against the release listings rather than guessed: whisper.cpp publishes
Win32 and x64 for Windows and nothing else, while llama.cpp does publish
bin-win-cpu-arm64.zip. So a Snapdragon machine gets a native cleanup model and
an emulated transcriber, which is slow enough that the cloud is the better
answer there, and neither the code nor the README said so.

The test pins it, so that a whisper.cpp release which does start publishing an
arm64 build turns the choice red rather than being quietly ignored.

ggml.py

@@ -251,6 +251,10 @@ def _wanted_assets(program):
             # as fast as the stock one, and it carries everything it needs.
             # Full names, because "bin-x64.zip" alone would also match the
             # CUDA archives, whichever the release happened to list first.
+            #
+            # x64 whatever this machine is, because whisper.cpp publishes no
+            # arm64 build for Windows: a Snapdragon runs this one emulated,
+            # which is slow but is the only local option there is.
             return ("whisper-blas-bin-x64.zip", "whisper-bin-x64.zip")
         if _has_vulkan() and arch == "x64":
             return ("bin-win-vulkan-x64.zip", f"bin-win-cpu-{arch}.zip")