Add Dependabot for GitHub Actions updates

Automatically keep GitHub Actions versions up to date
with weekly update checks.

Assisted-by: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Stephane Bouchet <sbouchet@redhat.com>

Author: sbouchet

.github/dependabot.yml

@@ -0,0 +1,18 @@
+#
+# Copyright (c) 2026 Red Hat, Inc.
+# This program and the accompanying materials are made
+# available under the terms of the Eclipse Public License 2.0
+# which is available at https://www.eclipse.org/legal/epl-2.0/
+#
+# SPDX-License-Identifier: EPL-2.0
+#
+# Contributors:
+#   Red Hat, Inc. - initial API and implementation
+#
+
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"