Bump keytar from 5.5.0 to 5.6.0 in /app

Bumps [keytar](https://github.com/atom/node-keytar) from 5.5.0 to 5.6.0.
- [Release notes](https://github.com/atom/node-keytar/releases)
- [Commits](https://github.com/atom/node-keytar/compare/v5.5.0...v5.6.0)

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

app/package.json

@@ -28,7 +28,7 @@
     "electron-updater": "^4.3.1",
     "fontmanager-redux": "0.4.0",
     "js-yaml": "3.13.1",
-    "keytar": "^5.5.0",
+    "keytar": "^5.6.0",
     "mz": "^2.7.0",
     "ngx-toastr": "^12.0.1",
     "node-pty": "^0.10.0-beta8",