ipa-healthcheck fails with AttributeError: module 'datetime' has no attribute 'UTC' after RHEL 9.6 and IdM update

Issue

• After updating IdM server to RHEL 9.6, ipa-healthcheck returns AttributeError: module 'datetime' has no attribute 'UTC' error when performing ReplicationCheck:

  "source": "ipahealthcheck.ds.replication",
  "check": "ReplicationCheck",
  "result": "CRITICAL",
  "uuid": "62491048-bb7a-46c3-b404-b1ab258257cc",
  "when": "20250926004937Z",
  "duration": "0.770483",
  "kw": {
    "exception": "module 'datetime' has no attribute 'UTC'",
    "traceback": "Traceback (most recent call last):\n  File \"/usr/lib/python3.9/site-packages/ipahealthcheck/core/core.py\", line 56, in run_plugin\n    for result in plugin.check():\n  File \"/usr/lib/python3.9/site-packages/ipahealthcheck/core/plugin.py\", line 18, in wrapper\n    for result in f(*args, **kwds):\n  File \"/usr/lib/python3.9/site-packages/ipahealthcheck/ds/plugin.py\", line 108, in check\n    results = self.doCheck(self.check_class, self.many)\n  File \"/usr/lib/python3.9/site-packages/ipahealthcheck/ds/plugin.py\", line 97, in doCheck\n    for result in results:\n  File \"/usr/lib/python3.9/site-packages/lib389/_mapped_object_lint.py\", line 126, in lint\n    yield from f()\n  File \"/usr/lib/python3.9/site-packages/lib389/replica.py\", line 1325, in _lint_no_ruv\n    ruv_dict = ruv.format_ruv()\n  File \"/usr/lib/python3.9/site-packages/lib389/replica.py\", line 949, in format_ruv\n    \"csn\": RUV().parse_csn(self._rid_csn.get(rid, '00000000000000000000')),\n  File \"/usr/lib/python3.9/site-packages/lib389/replica.py\", line 920, in parse_csn\n    time_str = datetime.datetime.fromtimestamp(timestamp, datetime.UTC).strftime('%Y-%m-%d %H:%M:%S')\nAttributeError: module 'datetime' has no attribute 'UTC'\n"
  }