[FIX] purchase: no bulgarian for en_GB translation

The translation of purchase.order().notes name (Terms and Conditions) is
wrongly done in bulgarian since 2016
(d14efd56).

opw-2719178

closes odoo/odoo#81985

Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>

addons/purchase/i18n/en_GB.po

@@ -1401,7 +1401,7 @@ msgstr ""
 #. module: purchase
 #: model:ir.model.fields,field_description:purchase.field_purchase_order_notes
 msgid "Terms and Conditions"
-msgstr "Положения и условия"
+msgstr ""
 
 #. module: purchase
 #: model_terms:ir.actions.act_window,help:purchase.product_normal_action_puchased