Bump keytar from 7.8.0 to 7.9.0 in /app

Bumps [keytar](https://github.com/atom/node-keytar) from 7.8.0 to 7.9.0.
- [Release notes](https://github.com/atom/node-keytar/releases)
- [Commits](https://github.com/atom/node-keytar/compare/v7.8.0...v7.9.0)

---
updated-dependencies:
- dependency-name: keytar
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

app/package.json

@@ -25,7 +25,7 @@
     "fontmanager-redux": "1.1.0",
     "glasstron": "0.0.7",
     "js-yaml": "4.1.0",
-    "keytar": "^7.8.0",
+    "keytar": "^7.9.0",
     "mz": "^2.7.0",
     "native-process-working-directory": "^1.0.2",
     "npm": "6",