ci: don't gate Windows CI on packaging job (#13338)

I already removed the dependency for the Unix jobs, but I forgot to
update the Windows matrix. There's no point starting the Windows
jobs 1.5 minutes late by waiting for the packaging jobs to complete.

Author: ichard26

.github/workflows/ci.yml

@@ -164,7 +164,7 @@ jobs:
     name: tests / ${{ matrix.python }} / ${{ matrix.os }} / ${{ matrix.group.number }}
     runs-on: ${{ matrix.os }}-latest
 
-    needs: [packaging, determine-changes]
+    needs: [determine-changes]
     if: >-
       needs.determine-changes.outputs.tests == 'true' ||
       github.event_name != 'pull_request'