Bump junit version to 5.12.1

Author: yuokada

build.gradle

@@ -28,6 +28,8 @@ description = "Embulk plugin for generate dummy records by Java."
 sourceCompatibility = 1.8
 targetCompatibility = 1.8
 
+def JUNIT_VERSION = "5.12.1"
+
 tasks.withType(JavaCompile) {
   options.compilerArgs << "-Xlint:deprecation" << "-Xlint:unchecked"
 }
@@ -46,8 +48,8 @@ dependencies {
   implementation 'com.google.guava:guava:33.4.0-jre'
   implementation 'org.msgpack:msgpack-core:0.9.+'
 
-  testImplementation "org.junit.jupiter:junit-jupiter-api:5.12.0"
-  testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:5.12.1"
+  testImplementation "org.junit.jupiter:junit-jupiter-api:$JUNIT_VERSION"
+  testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$JUNIT_VERSION"
 }
 
 embulkPlugin {