Datatracker fails without informative error message on draft submission

[kesara]

Describe the issue

When draft front > date only has a year attribute and the year is not the current year, Example:

<rfc ..>
 <front>
  ...
  <date year="2023">
  ...

Datatracker fails with an error message: Submission rejected: A system error occurred while processing the submission.

Under the hood code fails with following logs:

[2024-02-26 14:10:34,872: WARNING/ForkPoolWorker-2]     ietf/submit/utils.py(1327) in process_and_validate_submission(): Traceback (most recent call last):

  File "/workspace/ietf/submit/utils.py", line 1264, in process_and_validate_submission

    xml_metadata = process_submission_xml(submission.name, submission.rev)

  File "/workspace/ietf/submit/utils.py", line 1165, in process_submission_xml

    "document_date": xml_draft.get_creation_date(),

  File "/workspace/ietf/utils/xmldraft.py", line 165, in get_creation_date

    return self.parse_creation_date(self.xmlroot.find("front/date"))

  File "/workspace/ietf/utils/xmldraft.py", line 162, in parse_creation_date

    return datetime.date(year, month, day)

TypeError: an integer is required (got type NoneType)

Code of Conduct

• [X] I agree to follow the IETF's Code of Conduct

[jennifer-richards]

We're collecting these over in #5696