[7.4.0] Path map non-direct children of tree artifacts during header discovery (#23745)

Fixes header inclusion errors with path mapping when including a header
that is a non-direct child of a tree artifact.

Fixes #23681

Closes #23690.

PiperOrigin-RevId: 678118252
Change-Id: I37f4d5e8827785b291b5655967afba8f2a673df2

Commit
https://github.com/bazelbuild/bazel/commit/9cfffdf5d002e566103127349b57cdf49ad16641



Co-authored-by: Fabian Meumertzheim <fabian@meumertzhe.im>