build: update nbsphinx requirement from <0.9.5,>=0.8.8 to >=0.8.8,<0.…

…9.6 (#777)

Updates the requirements on [nbsphinx](https://github.com/spatialaudio/nbsphinx) to permit the latest version.
- [Release notes](https://github.com/spatialaudio/nbsphinx/releases)
- [Changelog](https://github.com/spatialaudio/nbsphinx/blob/master/NEWS.rst)
- [Commits](spatialaudio/nbsphinx@0.8.8...0.9.5)

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

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

pyproject.toml

@@ -49,7 +49,7 @@ dynamic = ["version"]
 docs = [
   "ipykernel>=6.13.0",
   "nbconvert>=7.0.0,<7.17",
-  "nbsphinx>=0.8.8,<0.9.5",
+  "nbsphinx>=0.8.8,<0.9.6",
   "pandoc",
   "pybtex",
   "pydata-sphinx-theme>=0.12",