Bump koa-helmet from 4.2.0 to 5.2.0

Bumps [koa-helmet](https://github.com/venables/koa-helmet) from 4.2.0 to 5.2.0.
- [Release notes](https://github.com/venables/koa-helmet/releases)
- [Commits](https://github.com/venables/koa-helmet/compare/v4.2.0...v5.2.0)

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

package.json

@@ -61,7 +61,7 @@
     "koa-error": "^3.2.0",
     "koa-favicon": "~2.0.1",
     "koa-generic-session": "^2.0.1",
-    "koa-helmet": "^4.0.0",
+    "koa-helmet": "^5.2.0",
     "koa-logger": "~3.2.1",
     "koa-redis": "^4.0.0",
     "koa-router": "^7.4.0",