Address deprecation warnings

[theferrit32]

These are the ones that come up when running the tests. There may be others.

clinvar_ingest/api/model/requests.py:142
  /Users/kferrite/dev/clinvar-ingest/clinvar_ingest/api/model/requests.py:142: PydanticDeprecatedSince20: Pydantic V1 style `@validator` validators are deprecated. You should migrate to Pydantic V2 style `@field_validator` validators, see the migration guide for more details. Deprecated in Pydantic V2.0 to be removed in V3.0. See Pydantic V2 Migration Guide at https://errors.pydantic.dev/2.9/migration/
    @validator("root")

clinvar_ingest/api/model/requests.py:159
  /Users/kferrite/dev/clinvar-ingest/clinvar_ingest/api/model/requests.py:159: PydanticDeprecatedSince20: Pydantic V1 style `@validator` validators are deprecated. You should migrate to Pydantic V2 style `@field_validator` validators, see the migration guide for more details. Deprecated in Pydantic V2.0 to be removed in V3.0. See Pydantic V2 Migration Guide at https://errors.pydantic.dev/2.9/migration/
    @validator("root")

clinvar_ingest/api/status_file.py:25
  /Users/kferrite/dev/clinvar-ingest/clinvar_ingest/api/status_file.py:25: DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).
    timestamp: str = datetime.utcnow().isoformat(),

test/api/test_main.py:25
  /Users/kferrite/dev/clinvar-ingest/test/api/test_main.py:25: PytestUnknownMarkWarning: Unknown pytest.mark.integration - is this a typo?  You can register custom marks to avoid this warning - for details, see https://docs.pytest.org/en/stable/how-to/mark.html
    @pytest.mark.integration

test/api/test_main.py::test_copy_endpoint_success
  /Users/kferrite/dev/clinvar-ingest/test/api/test_main.py:28: DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).
    StepStatus.STARTED, StepName.COPY, datetime.utcnow().isoformat()

test/api/test_main.py::test_copy_endpoint_success
  /Users/kferrite/dev/clinvar-ingest/test/api/test_main.py:31: DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).
    StepStatus.SUCCEEDED, StepName.COPY, datetime.utcnow().isoformat()

test/api/test_main.py::test_copy_endpoint_success
  /Users/kferrite/dev/clinvar-ingest/test/api/test_main.py:66: DeprecationWarning: datetime.datetime.utcnow() is deprecated and scheduled for removal in a future version. Use timezone-aware objects to represent datetimes in UTC: datetime.datetime.now(datetime.UTC).
    timestamp=datetime.utcnow(),

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html