chore: bump junit5 from 5.11.4 to 6.1.0 (#386)

Bump JUnit Jupiter 5.11.4 → 6.1.0 alongside Platform 6.1.0. No code changes needed.

gradle/libs.versions.toml

@@ -10,7 +10,7 @@ androidxTestRunner = "1.7.0"
 androidxTestEspresso = "3.7.0"
 coroutines = "1.11.0"
 junit = "4.13.2"
-junit5 = "5.11.4"
+junit5 = "6.1.0"
 junitPlatform = "6.1.0"
 kotlin = "2.4.0"
 # standalone per KSP 2.0+ guidance — NOT kotlinVersion-kspVersion; easy