ci: add github-actions ecosystem to dependabot (#3271)

Author: hubcio

.github/dependabot.yml

@@ -35,3 +35,22 @@ updates:
         update-types:
           - "minor"
           - "patch"
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    rebase-strategy: "disabled"
+    commit-message:
+      prefix: "chore(deps): "
+    assignees:
+      - "apache/iggy-committers"
+    reviewers:
+      - "apache/iggy-committers"
+    groups:
+      minor-and-patch:
+        patterns:
+          - "*"
+        update-types:
+          - "minor"
+          - "patch"