Some refinements to versioning

Author: chalmerlowe

noxfile.py

@@ -35,6 +35,7 @@
 DEFAULT_PYTHON_VERSION = "3.14"
 
 UNIT_TEST_PYTHON_VERSIONS: List[str] = [
+    "3.9",
     "3.10",
     "3.11",
     "3.12",
@@ -54,7 +55,7 @@
 UNIT_TEST_EXTRAS: List[str] = []
 UNIT_TEST_EXTRAS_BY_PYTHON: Dict[str, List[str]] = {}
 
-SYSTEM_TEST_PYTHON_VERSIONS: List[str] = ["3.10", "3.14"]
+SYSTEM_TEST_PYTHON_VERSIONS: List[str] = ["3.9", "3.14"]
 SYSTEM_TEST_STANDARD_DEPENDENCIES: List[str] = [
     "mock",
     "pytest",

owlbot.py

@@ -27,8 +27,8 @@
 # Add templated files
 # ----------------------------------------------------------------------------
 templated_files = common.py_library(
-    unit_test_python_versions=["3.10", "3.11", "3.12", "3.13", "3.14"],
-    system_test_python_versions=["3.10", "3.14"],
+    unit_test_python_versions=["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"],
+    system_test_python_versions=["3.9", "3.14"],
     default_python_version="3.14",
     cov_level=98,
     intersphinx_dependencies={