Update pytest requirement from <7 to <8

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@6.2.0...7.0.0)

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

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

Author: dependabot[bot]

setup.py

@@ -108,7 +108,7 @@
     install_requires=install_requires,
     extras_require=extras_require,
     test_suite="tests",
-    tests_require=["pytest<7"],
+    tests_require=["pytest<8"],
     entry_points={
         "console_scripts": [
             "schema-salad-tool=schema_salad.main:main",