Update sphinx requirement from <8,>=7 to >=7,<9

Updates the requirements on [sphinx](https://github.com/sphinx-doc/sphinx) to permit the latest version.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v7.0.0...v8.0.2)

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

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

pyproject.toml

@@ -62,7 +62,7 @@ dev = [
 ]
 docs = [
     "myst-parser",
-    "sphinx>=7,<8",
+    "sphinx>=7,<9",
     "sphinx-autodoc-typehints",
     "sphinx_rtd_theme>=1.3",
 ]