fix: add bzlmod use_repo of org_golang_x_sys (#896)

Commit 3c121a9 broke E2E tests with the
following error:

```
(23:31:56) ERROR: no such package '@@[unknown repo 'org_golang_x_sys' requested from @@aspect_bazel_lib~]//unix': The repository '@@[unknown repo 'org_golang_x_sys' requested from @@aspect_bazel_lib~]' could not be resolved: No repository visible as '@org_golang_x_sys' from repository '@@aspect_bazel_lib~'
```

The build worked when operating within the `aspect_bazel_lib` repo
itself, but not when importing it with Bzlmod. This is because the
`org_golang_x_sys` repo is imported indirectly by `rules_go`'s
`go_rules_dependencies` macro in the `WORKSPACE` file, which is still
active under bzlmod because there is no `WORKSPACE.bzlmod` file to
suppress it.

MODULE.bazel

@@ -66,6 +66,7 @@ use_repo(
     go_deps,
     "com_github_bmatcuk_doublestar_v4",
     "org_golang_x_exp",
+    "org_golang_x_sys",
 )
 
 host = use_extension("@aspect_bazel_lib//lib:extensions.bzl", "host", dev_dependency = True)