chore(deps): Update pytest requirement

Updates the requirements on [pytest](https://github.com/pytest-dev/pytest) to permit the latest version.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@8.4.2...9.0.1)

---
updated-dependencies:
- dependency-name: pytest
  dependency-version: 9.0.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

pyproject.toml

@@ -14,7 +14,7 @@ Repository = "https://github.com/team23/async-signals"
 
 [dependency-groups]
 dev = [
-    "pytest>=8.4.2,<9.0.0",
+    "pytest>=8.4.2,<10.0.0",
     "pytest-cov>=7.0.0,<8",
     "pytest-mock>=3.15.1,<4",
     "anyio[trio]>=4.11.0,<5.0.0",