chore: release 2.2.4 (#242)

🤖 I have created a release \*beep\* \*boop\*
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### [2.2.4](https://www.github.com/googleapis/nodejs-cloudbuild/compare/v2.2.3...v2.2.4) (2021-06-24)


### Bug Fixes

* make request optional in all cases ([#241](https://www.github.com/googleapis/nodejs-cloudbuild/issues/241)) ([c96003a](https://www.github.com/googleapis/nodejs-cloudbuild/commit/c96003a4897d3f7c8181a56c273b842a4dcdfbf7))
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This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please).

cloudbuild/package.json

@@ -15,7 +15,7 @@
     "test": "c8 mocha system-test --timeout=800000"
   },
   "dependencies": {
-    "@google-cloud/cloudbuild": "^2.2.3"
+    "@google-cloud/cloudbuild": "^2.2.4"
   },
   "devDependencies": {
     "c8": "^7.0.0",