[main] (deps): Bump src/submodules/googletest (#41796)

Bumps [src/submodules/googletest](https://github.com/google/googletest) from `5126f71` to `8d51dc5`.
- [Release notes](https://github.com/google/googletest/releases)
- [Commits](google/googletest@5126f71...8d51dc5)

---
updated-dependencies:
- dependency-name: src/submodules/googletest
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]