fix: leverage windows-11-arm for Windows ARM builds (#3062)

This is in support of https://github.com/openai/codex/issues/2979.

Once we have a release out, we can update the npm module and the VS Code
extension to take advantage of this.

.github/dotslash-config.json

@@ -21,6 +21,10 @@
         "windows-x86_64": {
           "regex": "^codex-x86_64-pc-windows-msvc\\.exe\\.zst$",
           "path": "codex.exe"
+        },
+        "windows-aarch64": {
+          "regex": "^codex-aarch64-pc-windows-msvc\\.exe\\.zst$",
+          "path": "codex.exe"
         }
       }
     }