Add option to restrict users maximum expiry duration for uploads

[Zarox28]

Hello,

As an administrator, I would like to have the ability to set a maximum expiry duration that users can configure for:

• Uploaded files

Currently, Zipline allows setting a default expiry time, but there is no backend restriction to prevent users from choosing a value that is too far in the future (e.g., more than 1 year).

This feature would help:

• Maintain better control of resources
• Prevent abuse (uploaded files staying active for excessive periods)
• Promote good service hygiene

Expected behavior:

• An admin setting to define the maximum allowed expiry duration (e.g.: 365 days, 90 days…)
• If a user tries to set a longer expiry (via UI or API), the server should reject the request and return a clear error message

I opened a PR (#934) ^^

Thank you for your consideration!