chore: add Dependabot cooldown — Python (pip) (#8)

* chore: add dependabot cooldown (ADR-011)

* fix: restrict dependabot cooldown to external packages (ADR-011)

Author: andrei-ifrim

.github/dependabot.yml

@@ -20,4 +20,8 @@ updates:
       interval: daily
       time: "09:00"
       timezone: Europe/London
+    cooldown:
+      default-days: 3
+      exclude:
+        - onb*
     open-pull-requests-limit: 10