Add dependabot.yml file

This is because the default configuration only picked up the requirements.txt

Author: ndevenish

.github/dependabot.yml

@@ -0,0 +1,7 @@
+version: 2
+updates:
+  - package-ecosystem: "uv"
+    directory: "/"
+    open-pull-requests-limit: 0
+    schedule:
+      interval: "quarterly"