[Bug]: better error message when virtual store not created by npm_link_all_packages

### What happened?

Here's a repro:

https://github.com/aspect-build/rules_ts/compare/fetch_subpkg

```shell
alexeagle@system76-pc:~/Projects/rules_ts$ cd e2e/bzlmod
alexeagle@system76-pc:~/Projects/rules_ts/e2e/bzlmod$ bazel fetch ...
ERROR: Evaluation of query "deps(...)" failed: preloading transitive closure failed: no such target '//:.aspect_rules_js/node_modules/long@5.2.1': target '.aspect_rules_js/node_modules/long@5.2.1' not declared in package '' defined by /home/alexeagle/Projects/rules_ts/e2e/bzlmod/BUILD (Tip: use `query "//:*"` to see all the targets in that package)
```

### Version

rules_js 1.8.0 and 1.11.1 at least

Reproduce the failure from e2e/bzlmod with bazel fetch ... and inspect the npm_link_all_packages entry point. Trace the missing .aspect_rules_js/node_modules/long@5.2.1 target from the reported BUILD error, then make the failure explain that the virtual store was not created and verify the repro produces the clearer message.

Written by the indexing model from the issue text.