Update sparse requirement from <=0.14 to <=0.15.1

Updates the requirements on [sparse](https://github.com/pydata/sparse) to permit the latest version.
- [Changelog](https://github.com/pydata/sparse/blob/main/docs/changelog.rst)
- [Commits](pydata/sparse@0.0.1...0.15.1)

---
updated-dependencies:
- dependency-name: sparse
  dependency-type: direct:production
...

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

pyproject.toml

@@ -59,7 +59,7 @@ dependencies = [
   "rechunker",
   "scipy",
   "shapely>=2.0",
-  "sparse<=0.14",
+  "sparse<=0.15.1",
   "toolz",
   "xarray<2023.11.0", # FIXME: Remove when pandas 2.2 is released and xclim is fixed.
   "xclim>=0.46.0",