docs: https://bazel.build/concepts/dependencies still refers to old style directory labels

### Description of the feature request:

https://bazel.build/concepts/dependencies#using-labels-reference-directories (and its pre-move equivalent https://docs.bazel.build/versions/main/build-ref.html#label_directory) still refer to labels pointing to directories with the old syntax like `data = ["testdata/."]`, mentioning them being present in the bazel source code. As far as I can tell there are no such references in the bazel codebase anymore. In addition to that since https://github.com/bazelbuild/bazel/issues/1025 has been solved directories should now be able to be referred to with the regular label syntax as if they were files.

The documentation as is makes it confusing as it implies labels referring to directories need to use that outdated syntax and have caveats which I don't think are true anymore.

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

Incorrect documentation.

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

macOS

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

release 5.0.0- (@non-git)

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

From nix: https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/tools/build-managers/bazel/bazel_5/default.nix

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

```text
git@github.com:bazelbuild/bazel.git
c282526c071389cd6f88cb77565283b257316267
0f5dc111be06b2ee8694640f400b58e12bfa5fea
```

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

No.

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

_No response_

Start with the linked documentation section at bazel.build/concepts/dependencies#using-labels-reference-directories and compare it with the current label behavior described in issue #1025. Update the directory-label guidance and remove obsolete syntax or caveats; done means the documentation matches current Bazel behavior and no longer points readers to outdated source references.

Written by the indexing model from the issue text.