build(deps-dev): update @types/express requirement

Updates the requirements on [@types/express](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/express) to permit the latest version.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/express)

packages/karma-runner/package.json

@@ -34,7 +34,7 @@
     "@stryker-mutator/jasmine-framework": "^2.0.0",
     "@stryker-mutator/test-helpers": "^2.0.0",
     "@stryker-mutator/util": "^2.0.0",
-    "@types/express": "~4.16.0",
+    "@types/express": "~4.17.0",
     "@types/semver": "~6.0.0",
     "jasmine-core": "~3.4.0",
     "karma": "~4.1.0",