chore: release 2.4.0 (#533)

🤖 I have created a release \*beep\* \*boop\*
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## [2.4.0](https://www.github.com/googleapis/java-dlp/compare/v2.3.4...v2.4.0) (2021-05-31)


### Features

* add `gcf-owl-bot[bot]` to `ignoreAuthors` ([#531](https://www.github.com/googleapis/java-dlp/issues/531)) ([5bc1ab9](https://www.github.com/googleapis/java-dlp/commit/5bc1ab99c9f145d6f1becb05869b8be682821afa))


### Dependencies

* update dependency com.google.cloud:google-cloud-shared-dependencies to v1.2.0 ([#532](https://www.github.com/googleapis/java-dlp/issues/532)) ([2a82b38](https://www.github.com/googleapis/java-dlp/commit/2a82b38d4b46f6145f8d1dc298dc52b819360afd))
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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).

dlp/snippets/snapshot/pom.xml

@@ -28,7 +28,7 @@
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-dlp</artifactId>
-      <version>2.3.5-SNAPSHOT</version>
+      <version>2.4.0</version>
     </dependency>
     <!-- {x-version-update-end} -->