Update Renovate config to ignore JUnit 6 which requires Java 17+ (#314)

Author: trask

.github/renovate.json5

@@ -28,6 +28,7 @@
       // junit 6+ requires Java 17+
       matchPackageNames: [
         'org.junit:**',
+        'org.junit.jupiter:**',
       ],
       matchUpdateTypes: [
         'major',