[FIX] google_calendar: avoid browse(False) instead of void records

If no partner is found for a given email after calling '_mail_search_on_user'
and '_mail_find_partner_from_emails' the returned result is a void recordset
for the email.

When rebrowsing partners afterwards, browsing p.id for each partner leads
to potentially browsing False, which gives a different recordset from a
void recordset. This further causes a crash in '_write_from_google' as
he considers [False] as not being void.

This commit fixes that by correctly filtering out void partners. This is
globally a followup of odoo/odoo#99330.

Task-3453577 (TestMail: Update Alias/Gateway tests for MC)
Prepares Task-36879 (Mail: Support MultiCompany Aliases)

Part-of: odoo/odoo#130768

addons/google_calendar/models/google_sync.py

@@ -310,7 +310,7 @@ class GoogleSync(models.AbstractModel):
                      email not in [partner.email_normalized for partner in partners]]
         if remaining:
             partners += self.env['mail.thread']._mail_find_partner_from_emails(remaining, records=self, force_create=True)
-        unsorted_partners = self.env['res.partner'].browse([p.id for p in partners])
+        unsorted_partners = self.env['res.partner'].browse([p.id for p in partners if p.id])
         # partners needs to be sorted according to the emails order provided by google
         k = {value: idx for idx, value in enumerate(emails)}
         result = unsorted_partners.sorted(key=lambda p: k.get(p.email_normalized, -1))