Fix machine naming

Author: mdboom

.github/workflows/coverage.yml

@@ -31,7 +31,7 @@ env:
 jobs:
   coverage:
     name: Coverage
-    runs-on: "linux-x86_64-gpu-a100-latest-1"
+    runs-on: "linux-arm64-gpu-a100-latest-1"
     # Our self-hosted runners require a container
     # TODO: use a different (nvidia?) container
     container: