Bump JUnit to 6.0.1 (#4858)

Author: Glavo

HMCLBoot/build.gradle.kts

@@ -2,6 +2,10 @@ plugins {
     id("java-library")
 }
 
-tasks.withType<JavaCompile> {
+tasks.compileJava {
     options.release.set(8)
 }
+
+tasks.compileTestJava {
+    options.release.set(17)
+}

gradle/libs.versions.toml

@@ -19,7 +19,7 @@ java-info = "1.0"
 authlib-injector = "1.2.6"
 
 # testing
-junit = "5.13.4"
+junit = "6.0.1"
 jimfs = "1.3.0"
 
 # plugins