Aspects: Validation actions defined by aspects are only ran for the top level targets

### Description of the feature request:

See https://groups.google.com/g/bazel-discuss/c/TCo0msh1My4?pli=1 for an example.

If an aspect is used to generate [validation actions](https://bazel.build/extending/rules#validation_actions). i.e.,
```
return [
OutputGroupInfo(
_validation = depset(...)
]
```

The validation is only ran for the top level target, and not the transitive dependencies. This makes it difficult to attach validators because we now need to construct a full shadow graph of all the nodes so we can manually propagate the `validation_output` from the leafs to the root node.

### Which category does this issue belong to?

Core

### What underlying problem are you trying to solve with this feature?

Make attaching validation actions using aspects more intuitive. This issue, along with https://github.com/bazelbuild/bazel/issues/19624 should allow us to have multiple aspects easily add validations to the graph.

### Which operating system are you running Bazel on?

Linux

### What is the output of `bazel info release`?

6.2.0

### If `bazel info release` returns `development version` or `(@non-git)`, tell us how you built Bazel.

_No response_

### What's the output of `git remote get-url origin; git rev-parse master; git rev-parse HEAD` ?

_No response_

### Have you found anything relevant by searching the web?

_No response_

### Any other information, logs, or outputs that you want to share?

_No response_

Start with the linked Bazel validation-actions documentation and the bazel-discuss example, then inspect how aspects return OutputGroupInfo with the _validation group. The change is complete when validation actions produced by aspects also run for transitive dependencies without requiring a manually constructed shadow graph.

Written by the indexing model from the issue text.