[FIX] l10n_pl: fix tax report Poland

Instead of doing the difference between output tax and input tax, the tax report was doing the sum.
This commit fixes this computation without revamping the rest of the report

closes odoo/odoo#87763

Signed-off-by: Olivier Colson <oco@odoo.com>

addons/l10n_pl/data/account_tax_report_data.xml

@@ -166,14 +166,14 @@
     <record id="account_tax_report_line_do_przeniesienia" model="account.tax.report.line">
         <field name="name">Podatek - Do przeniesienia</field>
         <field name="sequence" eval="3"/>
-        <field name="formula">PLTAXC_04_16 + PLTAXC_05_18 + PLTAXC_06_20 + PLTAXC_09_24 + PLTAXC_10_26 + PLTAXC_11_28 + PLTAXC_12_32 + PLTAXD_02_42</field>
+        <field name="formula">PLTAXC_04_16 + PLTAXC_05_18 + PLTAXC_06_20 + PLTAXC_09_24 + PLTAXC_10_26 + PLTAXC_11_28 + PLTAXC_12_32 - PLTAXD_02_42</field>
         <field name="country_id" ref="base.pl"/>
     </record>
 
     <record id="account_tax_report_line_nad_naleznym" model="account.tax.report.line">
         <field name="name">Podatek - Nadwyżka naliczonego nad należnym</field>
         <field name="sequence" eval="1"/>
-        <field name="formula">PLTAXC_04_16 + PLTAXC_05_18 + PLTAXC_06_20 + PLTAXC_09_24 + PLTAXC_10_26 + PLTAXC_11_28 + PLTAXC_12_32 + PLTAXD_02_42</field>
+        <field name="formula">PLTAXC_04_16 + PLTAXC_05_18 + PLTAXC_06_20 + PLTAXC_09_24 + PLTAXC_10_26 + PLTAXC_11_28 + PLTAXC_12_32 - PLTAXD_02_42</field>
         <field name="parent_id" ref="account_tax_report_line_do_przeniesienia"/>
         <field name="country_id" ref="base.pl"/>
     </record>
@@ -181,7 +181,7 @@
     <record id="account_tax_report_line_do_US" model="account.tax.report.line">
         <field name="name">Podatek - Do wpłaty do US</field>
         <field name="sequence" eval="1"/>
-        <field name="formula">PLTAXC_04_16 + PLTAXC_05_18 + PLTAXC_06_20 + PLTAXC_09_24 + PLTAXC_10_26 + PLTAXC_11_28 + PLTAXC_12_32 + PLTAXD_02_42</field>
+        <field name="formula">PLTAXC_04_16 + PLTAXC_05_18 + PLTAXC_06_20 + PLTAXC_09_24 + PLTAXC_10_26 + PLTAXC_11_28 + PLTAXC_12_32 - PLTAXD_02_42</field>
         <field name="parent_id" ref="account_tax_report_line_nad_naleznym"/>
         <field name="country_id" ref="base.pl"/>
     </record>