chore(otterdog): adding / updating file(s) due to blueprint require-dependabot

.github/dependabot.yml

@@ -1,13 +1,15 @@
-# Dependabot watches the Maven build and the workflow actions;
-# some dependency versions are managed by the parent pom
-# (org.osgi:org.osgi.maven.pom.parent).
+# Dependabot watches the Maven build; some dependency versions are
+# managed by the parent pom (org.osgi:org.osgi.maven.pom.parent).
+# The workflows are stubs from otterdog blueprints: their actions
+# live in osgi/.github and are updated there, not here.
 version: 2
 updates:
   - package-ecosystem: maven
     directory: "/"
     schedule:
       interval: weekly
-  - package-ecosystem: github-actions
-    directory: "/"
-    schedule:
-      interval: weekly
+    groups:
+      # Jupiter and Platform only work together: one pull request
+      junit:
+        patterns:
+          - "org.junit*"