hr_timesheet_view.xml

<?xml version="1.0"?>
<!-- Copyright 2020 Le Filament (<https://www.le-filament.com>)
     License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl). -->
<odoo>
    <data>
        
        <record id="hr_timesheet_line_tree_no_create" model="ir.ui.view">
            <field name="name">account.analytic.line.tree.no.create.inherited</field>
            <field name="model">account.analytic.line</field>
            <field name="inherit_id" ref="hr_timesheet.hr_timesheet_line_tree"/>
            <field name="arch" type="xml">
                <xpath expr="//field[@name='project_id']" position="attributes">
                    <attribute name="options">{'no_create': true, 'no_open': true,}</attribute>
                </xpath>
                <xpath expr="//field[@name='task_id']" position="attributes">
                    <attribute name="options">{'no_create': true, 'no_open': true,}</attribute>
                </xpath>
            </field>
       </record>

       <record id="hr_timesheet_line_form_no_create" model="ir.ui.view">
            <field name="name">account.analytic.line.form.no.create.inherited</field>
            <field name="model">account.analytic.line</field>
            <field name="inherit_id" ref="hr_timesheet.hr_timesheet_line_form"/>
            <field name="arch" type="xml">
                <xpath expr="//field[@name='project_id']" position="attributes">
                    <attribute name="options">{'no_create': true, 'no_open': true,}</attribute>
                </xpath>
                <xpath expr="//field[@name='task_id']" position="attributes">
                    <attribute name="options">{'no_create': true, 'no_open': true,}</attribute>
                </xpath>
            </field>
       </record>
       
   </data>
</odoo>