deps: update dependency io.grafeas:grafeas to v2.4.0 (#238)

* deps: update dependency io.grafeas:grafeas to v2.4.0

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pom.xml

@@ -86,7 +86,7 @@
       <dependency>
         <groupId>io.grafeas</groupId>
         <artifactId>grafeas</artifactId>
-        <version>2.3.1</version>
+        <version>2.4.0</version>
       </dependency>
       <dependency>
         <groupId>io.perfmark</groupId>