DEV: Update API calls to datetime functionality (#117)

* DEV: Update API calls to datetime functionality

* DEV: Use newer APIs for Python >= 3.11

* DEV: Use datetime API without depending upon Python version

* MISC: Remove unused import

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Brigitta Sipőcz <[email protected]>

jupyter_cache/cache/db.py

@@ -1,5 +1,5 @@
 from contextlib import contextmanager
-from datetime import datetime
+import datetime
 import os
 from pathlib import Path
 from typing import Any, Dict, List, Optional, Union
@@ -51,6 +51,10 @@ def get_version(path: Union[str, Path]) -> Optional[str]:
         return version_file.read_text().strip()
 
 
+def datetime_utcnow():
+    return lambda: datetime.datetime.now(datetime.timezone.utc)
+
+
 @contextmanager
 def session_context(engine: Engine):
     """Open a connection to the database."""
@@ -128,7 +132,7 @@ class NbProjectRecord(OrmBase):
     """A list of file assets required for the notebook to run."""
     exec_data = Column(JSON(), nullable=True)
     """Data on how to execute the notebook."""
-    created = Column(DateTime, nullable=False, default=datetime.utcnow)
+    created = Column(DateTime, nullable=False, default=datetime_utcnow())
     traceback = Column(Text(), nullable=True, default="")
     """A traceback is added if a notebook fails to execute fully."""
 
@@ -288,9 +292,9 @@ class NbCacheRecord(OrmBase):
     description = Column(String(255), nullable=False, default="")
     data = Column(JSON())
     """Extra data, such as the execution time."""
-    created = Column(DateTime, nullable=False, default=datetime.utcnow)
+    created = Column(DateTime, nullable=False, default=datetime_utcnow())
     accessed = Column(
-        DateTime, nullable=False, default=datetime.utcnow, onupdate=datetime.utcnow
+        DateTime, nullable=False, default=datetime_utcnow(), onupdate=datetime_utcnow()
     )
 
     def __repr__(self):
@@ -368,7 +372,7 @@ def touch(pk, db: Engine):
             record = session.query(NbCacheRecord).filter_by(pk=pk).one_or_none()
             if record is None:
                 raise KeyError(f"Cache record not found for NB with PK: {pk}")
-            record.accessed = datetime.utcnow()
+            record.accessed = datetime_utcnow()()
             session.commit()
 
     def touch_hashkey(hashkey, db: Engine):
@@ -379,7 +383,7 @@ def touch_hashkey(hashkey, db: Engine):
             )
             if record is None:
                 raise KeyError(f"Cache record not found for NB with hashkey: {hashkey}")
-            record.accessed = datetime.utcnow()
+            record.accessed = datetime_utcnow()()
             session.commit()
 
     @staticmethod