Entity ID for Font Assets is serialized twice which throws an error when using Debug Inspector

Steps to reproduce:

1. Open the attached project
2. Select the SairaStencil-Italic-VariableFont_wdth,wght SDF font asset
3. Switch the Inspector into Debug mode
4. Observe the Console window

Actual results: m_EntityId is serialised twice, which throws an error

Expected results: m_EntityId is not serialised twice, no errors or warnings are thrown after opening a Font Asset with Debug Inspector

Reproducible with versions: 6000.4.0a3, 6000.4.3f1, 6000.5.0b4, 6000.6.0a3

Not reproducible with versions: 6000.0.71f1, 6000.3.13f1, 6000.4.0a2

Tested on (OS): macOS 26.3.1

Full error message:

• The same field name is serialized multiple times in the class or its parent class. This is not supported: Base(MonoBehaviour) m_EntityId
  UnityEditor.GenericMenu:CatchMenu (object,string[],int)