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

Bumps [src/submodules/googletest](https://github.com/google/googletest) from `445e9bd` to `a6ce08a`.
- [Release notes](https://github.com/google/googletest/releases)
- [Commits](google/googletest@445e9bd...a6ce08a)

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

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

Author: dependabot[bot]