Immediately delete cuda-windows GitHub Artifacts (#22863)

### Summary

In #22848 and #22854 we could export and test on the same machine. We
can't do that here because the models are exported on Linux and tested
on Windows, so we still have to upload them for the Windows job to
download. This PR just deletes them once the Windows job is done.

GitHub charges for artifact storage by the hour. Each run uploads 18.4
GB, and right now that sits around for the full 2 days of retention even
though the Windows job is done with it within an hour. In August this
workflow ran about 70 times a day, so at that rate this brings us from
roughly **$650/month down to $12**. It also takes about 500 GB off our
live artifact storage.

If a test fails we leave the artifacts alone so you can still re-run the
failed jobs or debug. They expire with the normal retention (currently 2
days).

### Test plan

CI. The `delete-model-cuda-windows-artifacts` job should log six
deletions and the run should end with zero artifacts.

Author: jathu

.github/workflows/cuda-windows.yml

@@ -218,3 +218,27 @@ jobs:
 
           .ci/scripts/test_model_e2e_windows.ps1 -Device cuda-windows -HfModel '${{ matrix.model_repo }}/${{ matrix.model_name }}' -QuantName '${{ matrix.quant }}' -ModelDir \$artifactDir -ExpectedCudaVersion '13.0'
         }"
+
+  delete-model-cuda-windows-artifacts:
+    name: delete-model-cuda-windows-artifacts
+    # The exports exist only to hand the models to the Windows job above, about
+    # 18 GB per run, and GitHub bills artifact storage by the hour, so delete
+    # them as soon as the tests have consumed them instead of keeping them for
+    # the repository retention window. They are kept when a test fails so that
+    # "Re-run failed jobs" and debugging still have them; those expire with the
+    # retention window.
+    needs: [export-model-cuda-windows-artifact, test-model-cuda-windows-e2e]
+    runs-on: ubuntu-22.04
+    permissions:
+      actions: write
+    steps:
+      - name: Delete the exported models
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh api --paginate "repos/${{ github.repository }}/actions/runs/${{ github.run_id }}/artifacts" \
+            --jq '.artifacts[] | select(.name | test("-cuda-windows-")) | "\(.id) \(.name)"' |
+          while read -r id name; do
+            echo "Deleting ${name} (${id})"
+            gh api -X DELETE "repos/${{ github.repository }}/actions/artifacts/${id}"
+          done