Update indexed-gzip requirement from <=1.8 to <=1.8.7 (#405)

Updates the requirements on [indexed-gzip](https://github.com/pauldmccarthy/indexed_gzip) to permit the latest version.
- [Release notes](https://github.com/pauldmccarthy/indexed_gzip/releases)
- [Changelog](https://github.com/pauldmccarthy/indexed_gzip/blob/main/CHANGELOG.md)
- [Commits](pauldmccarthy/indexed_gzip@v0.1...v1.8.7)

---
updated-dependencies:
- dependency-name: indexed-gzip
  dependency-type: direct:production
...

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

pyproject.toml

@@ -19,7 +19,7 @@ requires-python = ">=3.10"
 dependencies = [
     'importlib_resources; python_version < "3.11"',
     "fmriprep >= 23.2, <= 24.0",
-    "indexed_gzip <= 1.8",
+    "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",