To remove editable in tree view you must use only tree string like below :
<tree string="Phone Calls" >
if you want to remove via inherit then try below exmple:
<record id="view_form_editable_list" model="ir.ui.view">
<field name="name">objectt.form.editable.list</field>
<field name="model">object.object</field>
<field name="inherit_id" ref="view_ref"/>
<field name="groups_id" eval="[(6, 0, [ref('groups_if_any_in_tree_view'),ref('groups_if_any_in_tree_view'),])]"/>
<field name="arch" type="xml">
<xpath expr="//field[@name='one2manyr_line']/tree" position="attributes">
<attribute name="editable"/>
</xpath>
</field>
</record
In groups_id you can add that groups which are in tree views fields so when this all applied group is active then editable is removed from tree view.