Fix low-severity zizmor finding: increase bundler cooldown default-days to 7

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: flavorjones

.github/dependabot.yml

@@ -17,7 +17,7 @@ updates:
     schedule:
       interval: weekly
     cooldown:
-      default-days: 3
+      default-days: 7
       semver-major-days: 7
       semver-minor-days: 3
       semver-patch-days: 2