starboard: Remove dead internal private build dependencies

[abhijeetk]

Delete build configurations for VirtualReality stubs, NPLB tests,
and related BUILD.gn targets. This change removes dead code
following the upstream deprecation and removal of VirtualReality
from the Starboard abstraction layer.(see: #2740).

Bug: 486791051
Bug: 487326366

[github-actions]

🤖 Gemini Suggested Commit Message

---

tvos: Remove dead VirtualReality build config

Delete build configurations for VirtualReality stubs, NPLB tests,
and related BUILD.gn targets. This change removes dead code
following the upstream deprecation and removal of VirtualReality
from the Starboard abstraction layer.

Bug: 486791051
Bug: 487326366

---

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[abhijeetk]

cc : @Gyuyoung @jkim-julie @rakuco

[gemini-code-assist]

Code Review

This pull request removes dead code and build configurations related to the deprecated VirtualReality feature. The changes are focused on removing conditional logic for is_internal_build and associated dependencies from several BUILD.gn files. The modifications are straightforward and align with the goal of cleaning up obsolete code. The changes appear correct and I see no issues.

[rakuco]

The PR title looks confusing to me: this patch is not tvOS-specific, and none of the changes reference VirtualReality specifically. Could you make it more generic?

[abhijeetk]

The PR title looks confusing to me: this patch is not tvOS-specific, and none of the changes reference VirtualReality specifically. Could you make it more generic?

Done. Update the PR title.