⬆️ Update pytest requirement from <8,>=7 to >=8,<9 (#867)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Chris Sewell <chrisj_sewell@hotmail.com>

pyproject.toml

@@ -70,15 +70,15 @@ rtd = [
 testing = [
     "beautifulsoup4",
     "coverage[toml]",
-    "pytest>=7,<8",
+    "pytest>=8,<9",
     "pytest-cov",
     "pytest-regressions",
     "pytest-param-files~=0.6.0",
     "sphinx-pytest",
 ]
 testing-docutils = [
     "pygments",
-    "pytest>=7,<8",
+    "pytest>=8,<9",
     "pytest-param-files~=0.6.0",
 ]