Upgrade junit dependency to 4.13.1

PiperOrigin-RevId: 336966883

Author: cushon

pom.xml

@@ -125,7 +125,7 @@
       <dependency>
         <groupId>junit</groupId>
         <artifactId>junit</artifactId>
-        <version>4.12</version>
+        <version>4.13.1</version>
         <scope>test</scope>
       </dependency>
       <dependency>