Bump electron from 9.1.2 to 9.4.0 in /test/window-integration-tests

Bumps [electron](https://github.com/electron/electron) from 9.1.2 to 9.4.0.
- [Release notes](https://github.com/electron/electron/releases)
- [Changelog](https://github.com/electron/electron/blob/master/docs/breaking-changes.md)
- [Commits](electron/electron@v9.1.2...v9.4.0)

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

Author: dependabot[bot]

test/window-integration-tests/package-lock.json

@@ -13,7 +13,7 @@
   },
   "license": "MIT",
   "dependencies": {
-    "electron": "9.1.2",
+    "electron": "9.4.0",
     "jest": "26.2.2",
     "spectron": "11.1.0"
   }