chore: Add Dependabot version-update cooldown

Author: ld-repository-standards[bot]

.github/dependabot.yml

@@ -0,0 +1,20 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    cooldown:
+      default-days: 7
+  - package-ecosystem: "gradle"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    cooldown:
+      default-days: 7
+  - package-ecosystem: "gradle"
+    directory: "/app"
+    schedule:
+      interval: "weekly"
+    cooldown:
+      default-days: 7