ci: dependabot

As we've now vendored our dependencies let's enable dependabot in the
same way we use it in our other Go projects.

Signed-off-by: Simon de Vlieger <supakeen@redhat.com>

.github/dependabot.yml

@@ -0,0 +1,26 @@
+# Basic test trying dependabot
+
+version: 2
+updates:
+
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      time: "04:00"
+    open-pull-requests-limit: 5
+    rebase-strategy: "disabled"
+
+  # Maintain dependencies for Go
+  - package-ecosystem: "gomod"
+    directory: "/"
+    schedule:
+      interval: "daily"
+      time: "04:00"
+    groups:
+      go-deps:
+        patterns:
+          - "*"  # group all dependency updates into one PR
+    open-pull-requests-limit: 1
+    rebase-strategy: "auto"