fix: handle expiration date in regard to changed timezones

[bahkauv70]

No description provided.

[bahkauv70]

Additional clarification: If the expiration_time is updated to the same date, but with a different notation, e.g. 2025-12-31T12:00:00+01:00 -> 2025-12-31T11:00:00Z, terraform will issue an update anyway, because:

• The plan is not empty (it still contains the no-op change to expiration_time)
• The computed attributes have to be updated
  There doesn't seem to be a officaly way to remove attributes from the plan explicitly. So an empty update is performed, but it won't change the state