NullReferenceException error is thrown on undoing after removing "New Render Objects" in CustomForwardRendererData.

Steps to repro:
1. Create a new URP template project.
2. Project Window > Click on "+" > Rendering.
3. Universal Render Pipeline > Forward Renderer > Add Renderer Feature.
4. Renderer Objects > Filters > LightMode Tags > Click on "+" > Remove.
5. Edit > Undo Add Element To Array.

Actual Result:
NullReferenceException is thrown in the console.

Expected Result:
No error in the console.

Reproducible in:
2021.2.0a7 with Package version 12.0.0.
2020.2.7f1 with Package version 10.3.1.
2019.4.21f1 with Package version 7.5.3, 7.5.2.

Working Fine in:
2021.1.0b10 with Package version 11.0.0.
2020.1.17f1 with Package version 9.0.0-preview.72, 8.3.1.
2019.4.21f1 with Package version 7.5.1, 7.4.3.

Environment:
Occurring on Windows 10 & Mac 10.15.

Stack trace:
NullReferenceException: SerializedObject of SerializedProperty has been Disposed.
UnityEditor.SerializedProperty.get_boolValue () (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.Rendering.Universal.StencilStateDataDrawer.GetPropertyHeight (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label) (at library/packagecache/com.unity.render-pipelines.universal@12.0.0/editor/renderstatedataeditor.cs:93)
UnityEditor.PropertyDrawer.GetPropertyHeightSafe (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label) (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.PropertyHandler.GetHeight (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren) (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.EditorGUI.GetPropertyHeightInternal (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren) (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.EditorGUI.GetPropertyHeight (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren) (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.EditorGUI.GetPropertyHeight (UnityEditor.SerializedProperty property) (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.Experimental.Rendering.Universal.RenderObjectsPassFeatureEditor.GetPropertyHeight (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label) (at library/packagecache/com.unity.render-pipelines.universal@12.0.0/editor/rendererfeatures/renderobjectspassfeatureeditor.cs:277)
UnityEditor.PropertyDrawer.GetPropertyHeightSafe (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label) (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.PropertyHandler.GetHeight (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren) (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.PropertyHandler.OnGUILayout (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren, UnityEngine.GUILayoutOption[] options) (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.EditorGUILayout.PropertyField (UnityEditor.SerializedProperty property, UnityEngine.GUIContent label, System.Boolean includeChildren, UnityEngine.GUILayoutOption[] options) (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.EditorGUILayout.PropertyField (UnityEditor.SerializedProperty property, System.Boolean includeChildren, UnityEngine.GUILayoutOption[] options) (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.Editor.DrawPropertiesExcluding (UnityEditor.SerializedObject obj, System.String[] propertyToExclude) (at <f15c002b2cec495b8970e8f0697e2c53>:0)
UnityEditor.Rendering.Universal.ScriptableRendererFeatureEditor.OnInspectorGUI () (at library/packagecache/com.unity.render-pipelines.universal@12.0.0/editor/scriptablerendererfeatureeditor.cs:11)
UnityEditor.Rendering.Universal.ScriptableRendererDataEditor.DrawRendererFeature (System.Int32 index, UnityEditor.SerializedProperty& renderFeatureProperty) (at library/packagecache/com.unity.render-pipelines.universal@12.0.0/editor/scriptablerendererdataeditor.cs:134)
UnityEditor.Rendering.Universal.ScriptableRendererDataEditor.DrawRendererFeatureList () (at library/packagecache/com.unity.render-pipelines.universal@12.0.0/editor/scriptablerendererdataeditor.cs:83)
UnityEditor.Rendering.Universal.ScriptableRendererDataEditor.OnInspectorGUI () (at library/packagecache/com.unity.render-pipelines.universal@12.0.0/editor/scriptablerendererdataeditor.cs:64)
UnityEditor.Rendering.Universal.ForwardRendererDataEditor.OnInspectorGUI () (at library/packagecache/com.unity.render-pipelines.universal@12.0.0/editor/forwardrendererdataeditor.cs:128)
UnityEditor.UIElements.InspectorElement+<>c__DisplayClass59_0.<CreateIMGUIInspectorFromEditor>b__0 () (at <44749ae58dc040f18a90d06a56b2d28f>:0)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)