chore(deps): update dependency isort to v9

Author: renovate[bot]

pyproject.toml

@@ -49,7 +49,7 @@ dev = [
     "pytest-mock==3.15.1",
     "mypy==2.3.1",
     "black==26.5.1",
-    "isort==8.0.1",
+    "isort==9.0.1",
     "ruff==0.16.6",
     "types-requests",
     "bump2version==1.0.1",