fixed UTC issue in Python 3.8

Author: prasad-sawantdesai

.github/workflows/test_with_pytest.yml

@@ -11,11 +11,11 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Set up Python ${{ matrix.python-version }}
 
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           # until saxonche is available in 3.13
           # https://saxonica.plan.io/issues/6561

imas/ids_convert.py

@@ -533,7 +533,8 @@ def _add_provenance_entry(
         # DD version after IMAS-5304
         node.reference.resize(len(node.reference) + 1, keep=True)
         node.reference[-1].name = source_txt
-        timestamp = datetime.datetime.now(datetime.UTC).isoformat(timespec="seconds")
+        utc = getattr(datetime, "UTC", datetime.timezone.utc)
+        timestamp = datetime.datetime.now(utc).isoformat(timespec="seconds")
         node.reference[-1].timestamp = timestamp.replace("+00:00", "Z")
     else:
         # DD before IMAS-5304 (between 3.34.0 and 3.41.0)