Update nibabel requirement from <=5.1 to <=5.2.1

Updates the requirements on [nibabel](https://github.com/nipy/nibabel) to permit the latest version.
- [Release notes](https://github.com/nipy/nibabel/releases)
- [Changelog](https://github.com/nipy/nibabel/blob/master/Changelog)
- [Commits](nipy/nibabel@brifti-0.1...5.2.1)

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

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

pyproject.toml

@@ -22,7 +22,7 @@ dependencies = [
     "indexed_gzip <= 1.8.7",
     "looseversion",
     "networkx ~= 3.3",  # nipype needs networkx, but 3+ isn"t compatible with nipype 1.8.5
-    "nibabel <= 5.1",
+    "nibabel <= 5.2.1",
     "nilearn ~= 0.10.3",
     "nipype >= 1.8.5",
     "nitransforms >= 21.0.0",