chore: release 2.3.1

* updated CHANGELOG.md [ci skip]

* updated package.json [ci skip]

* updated samples/package.json [ci skip]

Author: release-please[bot]

security-center/snippets/package.json

@@ -13,7 +13,7 @@
   },
   "license": "Apache-2.0",
   "dependencies": {
-    "@google-cloud/security-center": "^2.3.0"
+    "@google-cloud/security-center": "^2.3.1"
   },
   "devDependencies": {
     "chai": "^4.2.0",