chore: configure Dependabot to weekly checks and limit PRs

Changed Dependabot schedule to weekly and restricted open PRs to zero to minimize noise. This prepares for transitioning to Renovate for dependency updates management.

Author: ttypic

.github/dependabot.yml

@@ -3,5 +3,7 @@ updates:
   - package-ecosystem: 'npm'
     directory: '/'
     schedule:
-      interval: 'daily' # weekdays (Monday to Friday)
+      interval: 'weekly'
     labels: [] # prevent the default `dependencies` label from being added to pull requests
+    # Disable @dependabot (except for security updates) because it pollutes a list of PRs, we'll update CI to use @renovate instead
+    open-pull-requests-limit: 0