Bump scientific-python/attach-next-milestone-action from bc07be829f693829263e57d5e8489f4e57d3d420 to c9cfab10ad0c67fed91b01103db26b7f16634639 (#667)

Author: dependabot[bot]

.github/workflows/milestone-merged-prs.yaml

@@ -17,7 +17,7 @@ jobs:
       pull-requests: read
     runs-on: ubuntu-latest
     steps:
-      - uses: scientific-python/attach-next-milestone-action@bc07be829f693829263e57d5e8489f4e57d3d420
+      - uses: scientific-python/attach-next-milestone-action@c9cfab10ad0c67fed91b01103db26b7f16634639
         with:
           token: ${{ secrets.MILESTONE_LABELER_TOKEN }}
           force: true