Dynamic entity reference type selector does not inherit form state from target ID element

The Dynamic Entity Reference widgets render a target_type selector next to the main target_id autocomplete element.
When the target_id element is required, hidden, disabled, or conditionally controlled through #states, the target_type selector does not inherit the same form state. This can lead to inconsistent UX and validation feedback.
For example, a required Dynamic Entity Reference field can show the required marker and validation on target_id, while the target_type selector remains visually optional.
Proposed fix: Add an #after_build callback to the DER widget wrapper and synchronize selected form state properties from target_id to target_type:

• #required
• #access
• #disabled
• #states

This keeps both parts of the composite widget aligned, including cases where other form alters add state to target_id after the widget’s formElement() method runs.