fix(deps) ignore junit updates > 6.0.0

junit6 drops Java 8 support

Author: cgoetz-inovex

.github/dependabot.yml

@@ -10,6 +10,11 @@ updates:
     directory: "/"
     schedule:
       interval: "daily"
+    ignore:
+      - dependency-name: "org.junit.jupiter:junit-jupiter-api"
+        versions: ["[6.0.0,)"]
+      - dependency-name: "org.junit.jupiter:junit-jupiter-engine"
+        versions: ["[6.0.0,)"]
     cooldown:
         default-days: 7
         exclude: ["cloud.stackit*"]