Bump scientific-python/attach-next-milestone-action

Bumps [scientific-python/attach-next-milestone-action](https://github.com/scientific-python/attach-next-milestone-action) from a4889cfde7d2578c1bc7400480d93910d2dd34f6 to bc07be829f693829263e57d5e8489f4e57d3d420.
- [Release notes](https://github.com/scientific-python/attach-next-milestone-action/releases)
- [Commits](scientific-python/attach-next-milestone-action@a4889cf...bc07be8)

---
updated-dependencies:
- dependency-name: scientific-python/attach-next-milestone-action
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

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

@@ -12,7 +12,7 @@ jobs:
     name: attach to PR
     runs-on: ubuntu-latest
     steps:
-      - uses: scientific-python/attach-next-milestone-action@a4889cfde7d2578c1bc7400480d93910d2dd34f6
+      - uses: scientific-python/attach-next-milestone-action@bc07be829f693829263e57d5e8489f4e57d3d420
         with:
           token: ${{ secrets.MILESTONE_LABELER_TOKEN }}
           force: true