chore(deps): bump actions/setup-python from 6 to 7 (#220)

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 6 to 7.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v6...v7)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/upstream-ledger-sync.yml

@@ -26,7 +26,7 @@ jobs:
         run: |
           git remote add upstream https://github.com/langchain-ai/open-swe.git || true
 
-      - uses: actions/setup-python@v6
+      - uses: actions/setup-python@v7
         with:
           python-version: "3.12"