Update pytest requirement from ~=7.2 to ~=8.1

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@7.2.0...8.1.1)

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

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

pyproject.toml

@@ -10,7 +10,7 @@ classifiers = [
 dependencies = [
     "pyserini~=0.14.0",
     "dload~=0.6.0",
-    "pytest~=7.2",
+    "pytest~=8.1",
     "nltk~=3.7",
     "autopep8~=2.0",
     "pylint~=3.0",