chore(main): release 3.0.4 (#470)

* chore(main): release 3.0.4

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: release-please[bot]

scheduler/package.json

@@ -14,7 +14,7 @@
     "test": "mocha --timeout 10000 --exit"
   },
   "dependencies": {
-    "@google-cloud/scheduler": "^3.0.3",
+    "@google-cloud/scheduler": "^3.0.4",
     "body-parser": "^1.18.3",
     "express": "^4.16.4"
   },