Bump externals/googletest from 3d787f5 to 5a37b51

Bumps [externals/googletest](https://github.com/google/googletest) from `3d787f5` to `5a37b51`.
- [Release notes](https://github.com/google/googletest/releases)
- [Commits](google/googletest@3d787f5...5a37b51)

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

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