chore(deps-dev): bump electron from 28.3.3 to 39.8.4 in /electron-app

Bumps [electron](https://github.com/electron/electron) from 28.3.3 to 39.8.4.
- [Release notes](https://github.com/electron/electron/releases)
- [Commits](electron/electron@v28.3.3...v39.8.4)

---
updated-dependencies:
- dependency-name: electron
  dependency-version: 39.8.4
  dependency-type: direct:development
...

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Author: dependabot[bot]