MNTP does not respect min and max configuration

[kjac]

Which Umbraco version are you using? (Please write the exact version, example: 10.1.0)

V14 RC5

Bug summary

The "Minimum number of items" and "Maximum number of items" on an MNTP is not respected by the UI, nor by the server 😱

Given this configuration:

...I can save and publish documents with both 1 and 10 selected items.

Specifics

No response

Steps to reproduce

1. Create a doctype with an MNTP property, which has min and max items configured.
2. Create a document based on this doctype, and pick either too many or too few items.
3. Save and publish.

Expected result / actual result

It should be possible to save the document (with a warning to follow, stating that too many/too few items has been added?), but it should definitively not be possible to publish the document.

Both client and server should respect and validate the configuration, as a bare minimum at publish time.

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This item has been added to our backlog AB#41892