Bump external/benchmark from 24e0bd8 to 761305e

Bumps [external/benchmark](https://github.com/google/benchmark) from `24e0bd8` to `761305e`.
- [Release notes](https://github.com/google/benchmark/releases)
- [Commits](google/benchmark@24e0bd8...761305e)

---
updated-dependencies:
- dependency-name: external/benchmark
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>