Bazel-8.3.0 flags _copy_rule depending on @bazel_tools//src/conditions:host_windows_x64_constraint

```
WARNING: .../BUILD.bazel:9:11: in _write_xfile rule @@: target '@@' depends on deprecated target '@@bazel_tools//src/conditions:host_windows_x64_constraint': No longer used by Bazel and will be removed in the future. Migrate to toolchains or define your own version of this setting.
WARNING: /BUILD.bazel:205:11: in _copy_file rule depends on deprecated target '@@bazel_tools//src/conditions:host_windows_x64_constraint': No longer used by Bazel and will be removed in the future. Migrate to toolchains or define your own version of this setting.
```

I just saw this and wanted to ensure it was recorded. I haven't created a repro since it should be apparent in any example that upgrades to bazel-8.3.0

Reproduce a bazel-8.3.0 build, then inspect BUILD.bazel around lines 9 and 205, where _write_xfile and _copy_file trigger the warning. Trace how these rules depend on host_windows_x64_constraint and identify the supported replacement; done means the affected build no longer emits this deprecation warning.

Written by the indexing model from the issue text.