[BUG] Due date showing placeholders when modified

[mmarif4u]

Description

If you add a due date to an issue or pr and then modify it. It will show you the placeholders instead.

Screenshots

Gitea Version

1.17.1

Can you reproduce the bug on the Gitea demo site?

Yes

Operating System

No response

Browser Version

FF 103

[jolheiser]

This was fixed by #20388 and subsequent backport #21032