Fix pytest 3.9 CI constraint

Author: Copilot

requirements.txt

@@ -24,7 +24,7 @@ pydantic>=2.0.0,<3.0.0
 # pytest 9 requires Python >=3.10; keep <9 for Python 3.9 (pytest 9 dropped 3.9 support)
 # CVE-2025-71176 is fixed in 9.0.3 (only available for Python >=3.10)
 pytest>=9.0.3; python_version >= "3.10"
-pytest>=9.1.1,<10; python_version < "3.10"
+pytest>=7.4.0,<9; python_version < "3.10"
 pytest-django>=4.5.2
 pytest-asyncio>=0.21.1
 pytest-cov>=7.0.0