chore(deps): update dependency org.objenesis:objenesis to v2.6

Author: renovate-bot

graphql-java-servlet/build.gradle

@@ -35,7 +35,7 @@ dependencies {
     testImplementation "org.codehaus.groovy:groovy-all:2.4.1"
     testImplementation "org.spockframework:spock-core:1.1-groovy-2.4-rc-3"
     testRuntimeOnly "cglib:cglib-nodep:3.2.4"
-    testRuntimeOnly "org.objenesis:objenesis:2.5.1"
+    testRuntimeOnly "org.objenesis:objenesis:2.6"
     testImplementation "org.slf4j:slf4j-simple:$LIB_SLF4J_VER"
     testImplementation 'org.springframework:spring-test:4.3.7.RELEASE'
     testRuntimeOnly 'org.springframework:spring-web:4.3.7.RELEASE'