changed strategy for old python versions

Author: daniel-sanche

.kokoro/presubmit/system-3.8.cfg

@@ -209,6 +209,11 @@ def unit(session, protobuf_implementation):
     if protobuf_implementation == "cpp" and py_version >= (3, 11):
         session.skip("cpp implementation is not supported in python 3.11+")
 
+    # Skip python 3.7 and 3.8 tests if not available in kokoro environment
+    # TODO: remove when 3.7 and 3.8 are dropped
+    if py_version < (3, 9) and os.getenv("KOKORO_BUILD_ID"):
+        session.skip("skipping deprecated python versions")
+
     constraints_path = str(
         CURRENT_DIRECTORY / "testing" / f"constraints-{session.python}.txt"
     )

noxfile.py

@@ -109,7 +109,7 @@ def get_staging_dirs(
     system_test_external_dependencies=[
         "pytest-asyncio==0.21.2",
     ],
-    unit_test_python_versions=["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"],
+    unit_test_python_versions=["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13", "3.14"],
 )
 
 s.move(templated_files, excludes=[".coveragerc", "README.rst", ".github/release-please.yml", "noxfile.py", "renovate.json"])