Bump the dev-dependencies group across 1 directory with 2 updates

Updates the requirements on [ophyd-async](https://github.com/bluesky/ophyd-async) and [sphinx](https://github.com/sphinx-doc/sphinx) to permit the latest version.

Updates `ophyd-async` from 0.9.0a1 to 0.9.0a2
- [Release notes](https://github.com/bluesky/ophyd-async/releases)
- [Commits](bluesky/ophyd-async@v0.9.0a1...v0.9.0a2)

Updates `sphinx` to 8.1.3
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/v8.1.3/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v0.1.61611...v8.1.3)

---
updated-dependencies:
- dependency-name: ophyd-async
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dev-dependencies
- dependency-name: sphinx
  dependency-type: direct:production
  dependency-group: dev-dependencies
...

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

pyproject.toml

@@ -15,7 +15,7 @@ description = "Ophyd devices and other utils that could be used across DLS beaml
 dependencies = [
     "click",
     "ophyd",
-    "ophyd-async == 0.9.0a1",
+    "ophyd-async == 0.9.0a2",
     "bluesky",
     "pyepics",
     "dataclasses-json",
@@ -60,7 +60,7 @@ dev = [
     "pytest-cov",
     "pytest-random-order",
     "ruff",
-    "sphinx<7.4.6",              #  pinned due to https://github.com/sphinx-doc/sphinx/issues/12660
+    "sphinx<8.1.4",              #  pinned due to https://github.com/sphinx-doc/sphinx/issues/12660
     "sphinx-autobuild",
     "sphinx-copybutton",
     "sphinxcontrib-mermaid",