Improve output format of backend update PR

.github/workflows/update_backend.yml

@@ -44,31 +44,23 @@ jobs:
       - name: "Update versions"
         if: ${{ steps.get-latest.outputs.version != steps.get-current.outputs.version }}
         run: |
-          git config --global user.name "${GITHUB_ACTOR}"
-          git config --global user.email "${GITHUB_ACTOR}@users.noreply.github.com"
-
           # Bump PySR patch number:
-          CURRENT_PYSR_PATCH_VERSION=$(python -c 'import pysr; print(pysr.version.__version__.split(".")[-1])' 2>/dev/null)
+          CURRENT_PYSR_PATCH_VERSION=$(python -c 'import pysr; print(pysr.version.__version__.split(".")[-1], end="")' 2>/dev/null)
           NEW_PYSR_PATCH_VERSION=$((CURRENT_PYSR_PATCH_VERSION + 1))
-          sed -i "s/^__version__ = .*/__version__ = \"$(python -c 'import pysr; print(".".join(pysr.version.__version__.split(".")[:-1]))' 2>/dev/null).${NEW_PYSR_PATCH_VERSION}\"/" pysr/version.py
+          sed -i "s/^__version__ = .*/__version__ = \"$(python -c 'import pysr; print(".".join(pysr.version.__version__.split(".")[:-1]), end="")' 2>/dev/null).${NEW_PYSR_PATCH_VERSION}\"/" pysr/version.py
           
           # Set SymbolicRegression.jl version:
           sed -i "s/^__symbolic_regression_jl_version__ = .*/__symbolic_regression_jl_version__ = \"${{ steps.get-latest.outputs.version }}\"/" pysr/version.py
 
-          git add pysr/version.py
-          git commit -m "Update backend version to v${{ steps.get-latest.outputs.version }}"
-
       - name: "Create PR"
-        if: ${{ steps.get-latest.outputs.version != steps.get-current.outputs.version }}
         uses: peter-evans/create-pull-request@v3
         with:
           token: ${{ secrets.REPO_SCOPED_TOKEN }}
           title: "Automated update to backend: v${{ steps.get-latest.outputs.version }}"
           body: |
-            This PR was automatically generated by the GitHub Action
-            [PySR backend update](.github/workflows/update-backend.yml).
+            This PR was automatically generated by the GitHub Action `.github/workflows/update-backend.yml`
 
-            It updates the backend version to v${{ steps.get-latest.outputs.version }}.
-            For a full description of the changes, see the backend
-            changelog: [v${{ steps.get-latest.outputs.version }}](https://github.com/MilesCranmer/SymbolicRegression.jl/releases/tag/v${{ steps.get-latest.outputs.version }}).
+            It updates the backend version to v${{ steps.get-latest.outputs.version }}. For a full description of the changes, see the backend changelog: [v${{ steps.get-latest.outputs.version }}](https://github.com/MilesCranmer/SymbolicRegression.jl/releases/tag/v${{ steps.get-latest.outputs.version }}).
           delete-branch: true
+          commit-message: "Update backend version to v${{ steps.get-latest.outputs.version }}"
+          add-paths: pysr/version.py