Bump electron in /benchmark/02-empty-app-frameless/electron

Bumps [electron](https://github.com/electron/electron) from 39.0.0 to 39.2.4.
- [Release notes](https://github.com/electron/electron/releases)
- [Commits](electron/electron@v39.0.0...v39.2.4)

---
updated-dependencies:
- dependency-name: electron
  dependency-version: 39.2.4
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]