Bump electron from 39.7.0 to 39.8.5 in /examples/electron-app

Bumps [electron](https://github.com/electron/electron) from 39.7.0 to 39.8.5.
- [Release notes](https://github.com/electron/electron/releases)
- [Commits](electron/electron@v39.7.0...v39.8.5)

---
updated-dependencies:
- dependency-name: electron
  dependency-version: 39.8.5
  dependency-type: direct:development
...

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

Author: dependabot[bot]

examples/electron-app/package.json

@@ -31,7 +31,7 @@
   },
   "devDependencies": {
     "@theia/cli": "~1.70.0",
-    "electron": "39.7.0"
+    "electron": "39.8.5"
   },
   "theia": {
     "target": "electron",