feat(tests): Add optional cutoff to toxgen (#4243)

This will be useful to identify old versions of packages when we're
doing a deprecation round.

Author: sentrivana

scripts/populate_tox/populate_tox.py

@@ -9,7 +9,7 @@
 import time
 from bisect import bisect_left
 from collections import defaultdict
-from datetime import datetime, timezone
+from datetime import datetime, timedelta, timezone  # noqa: F401
 from importlib.metadata import metadata
 from packaging.specifiers import SpecifierSet
 from packaging.version import Version
@@ -29,6 +29,10 @@
 from split_tox_gh_actions.split_tox_gh_actions import GROUPS
 
 
+# Set CUTOFF this to a datetime to ignore packages older than CUTOFF
+CUTOFF = None
+# CUTOFF = datetime.now(tz=timezone.utc) - timedelta(days=365 * 5)
+
 TOX_FILE = Path(__file__).resolve().parent.parent.parent / "tox.ini"
 ENV = Environment(
     loader=FileSystemLoader(Path(__file__).resolve().parent),
@@ -162,9 +166,13 @@ def _prefilter_releases(
         if meta["yanked"]:
             continue
 
-        if older_than is not None:
-            if datetime.fromisoformat(meta["upload_time_iso_8601"]) > older_than:
-                continue
+        uploaded = datetime.fromisoformat(meta["upload_time_iso_8601"])
+
+        if older_than is not None and uploaded > older_than:
+            continue
+
+        if CUTOFF is not None and uploaded < CUTOFF:
+            continue
 
         version = Version(release)