Make artifact tests not flaky

Previously some of the artifact tests would fail, if the minute the assertion happened was different
from the minute the artifact was created.
Now we verify they happened within a minute of each other, so
this should be more robust.

tests/end_to_end/test_artifacts.py

@@ -1,4 +1,4 @@
-from datetime import datetime
+from datetime import datetime, timedelta
 
 from lineapy.utils.constants import VERSION_DATE_STRING
 
@@ -71,10 +71,11 @@ def test_get_artifact_has_version(execute):
 art_version = art.version
 """
     res = execute(code, snapshot=False)
-    # doing this because if the test runs at the edge of the second it fails sometimes
-    assert res.values["art_version"].startswith(
-        datetime.now().strftime("%Y-%m-%dT%H:%M:")
+    # Verify the version date is at most a minute from now but not in the future
+    artifact_version_delta = datetime.now() - datetime.fromisoformat(
+        res.values["art_version"]
     )
+    assert timedelta(minutes=0) < artifact_version_delta < timedelta(minutes=1)
     assert res.slice("x") == "x = 1\n"
 
 
@@ -107,9 +108,13 @@ def test_catalog_shows_all_versions(execute):
     # artifact_version and date_created might not match esp in future with named versions
     # but for default version it should be a string version of a date
     assert db_values[0]["date_created"] < db_values[1]["date_created"]
-    assert db_values[1]["artifact_version"].startswith(
-        datetime.now().strftime("%Y-%m-%dT%H:%M:")
+
+    # Verify the version date is at most a minute old but not in the future
+    artifact_version_delta = datetime.now() - datetime.fromisoformat(
+        db_values[1]["artifact_version"]
     )
+    assert timedelta(minutes=0) < artifact_version_delta < timedelta(minutes=1)
+
     # finally make sure the print property is updated to reflect versions
     assert res.values["all_print"] == "\n".join(
         [