chore: release 3.9.0 (#285)

🤖 I have created a release \*beep\* \*boop\*
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## [3.9.0](https://github.com/googleapis/nodejs-secret-manager/compare/v3.8.1...v3.9.0) (2021-07-30)


### Features

* In Secret Manager, users can now use filter to customize the output of ListSecrets/ListSecretVersions calls ([#283](https://github.com/googleapis/nodejs-secret-manager/issues/283)) ([063691a](https://github.com/googleapis/nodejs-secret-manager/commit/063691a87291fab82037e9b444812dcf0724eb0c))
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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).

secret-manager/package.json

@@ -14,7 +14,7 @@
     "test": "c8 mocha --recursive test/ --timeout=800000"
   },
   "dependencies": {
-    "@google-cloud/secret-manager": "^3.8.1"
+    "@google-cloud/secret-manager": "^3.9.0"
   },
   "devDependencies": {
     "c8": "^7.0.0",