Group Dependabot updates into single weekly PR (#215)

* Initial plan

* chore: group dependabot updates into single weekly PR

Co-authored-by: noahtigner <46695778+noahtigner@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: noahtigner <46695778+noahtigner@users.noreply.github.com>

Author: Copilot

.github/dependabot.yml

@@ -9,3 +9,7 @@ updates:
     directory: '/' # Location of package manifests
     schedule:
       interval: 'weekly'
+    groups:
+      all-dependencies:
+        patterns:
+          - '*'