chore(deps): update actions/upload-artifact digest to b4b15b8 (#51)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/build.yaml

@@ -21,7 +21,7 @@ jobs:
           python -m pip install -e .[docs]
           sphinx-build -b html docs/ docs/_build
       - name: Upload artifact
-        uses: actions/upload-artifact@604373da6381bf24206979c74d06a550515601b9 # v4
+        uses: actions/upload-artifact@b4b15b8c7c6ac21ea08fcf65892d2ee8f75cf882 # v4
         with:
           name: docs
           path: docs/_build/