Automated submodule update: vrs (#163)

Summary:
This is an automated pull request to update the first-party submodule for [facebookresearch/vrs](https://github.com/facebookresearch/vrs).

New submodule commit: facebookresearch/vrs@1c87e02

Pull Request resolved: #163

Test Plan: Ensure that CI jobs succeed on GitHub before landing.

Reviewed By: georges-berenger

Differential Revision: D70831195

fbshipit-source-id: 86bfb8376ffaec5362244cd4f208f762556edd6b