[FIX] contract: multi-company assignment notification

Steps to reproduce the problem:

1. Log in as Mitchell Admin.
2. Create contract CNT-A for company CMP-A, assigned to Marc Demo.
3. Create contract CNT-B for company CMP-B, assigned to Marc Demo.
4. Run cron to create recurring invoices.

Actual results:

- Odoo sends automated assignment emails to Marc Demo, which indicate the name of the company activated for `__system__` user whlie the cron was being executed.

Expected results after this patch:

- Odoo sends automated assignment emails to Marc Demo, which indicate the invoice company.

@Tecnativa TT24657

contract/static/description/index.html

@@ -425,6 +425,7 @@ To use it, just select the template on the contract and fields will be filled au
 <h1><a class="toc-backref" href="#id3">Known issues / Roadmap</a></h1>
 <ul class="simple">
 <li>Recover states and others functional fields in Contracts.</li>
+<li>Remove <tt class="docutils literal">models/ir_ui_view.py</tt> in v13, where the workaround it contains is supported upstream.</li>
 </ul>
 </div>
 <div class="section" id="bug-tracker">