fix(India): Sales Invoice with duplicate items not showing correct taxable value

[deepeshgarg007]

Taxable value for Invoices having the same items multiple times was incorrectly shown

Steps to replicate:

1. Create a GST invoice with the same item added multiple times

2. Check GSTR-1 Report

Before:

The expected total value is 5000 as the base net total is 5000

After:

Got taxable value as expected

[codecov]

Codecov Report

Merging #28334 (0dca97e) into develop (c96b549) will increase coverage by 0.09%.
The diff coverage is 0.00%.

@@             Coverage Diff             @@
##           develop   #28334      +/-   ##
===========================================
+ Coverage    55.17%   55.26%   +0.09%     
===========================================
  Files         1119     1119              
  Lines        66539    66538       -1     
===========================================
+ Hits         36711    36775      +64     
+ Misses       29828    29763      -65     

Impacted Files	Coverage Δ
erpnext/regional/report/gstr_1/gstr_1.py	0.00% <0.00%> (ø)
...value/warehouse_wise_item_balance_age_and_value.py	92.40% <0.00%> (-2.54%)	⬇️
.../report/stock_projected_qty/stock_projected_qty.py	86.84% <0.00%> (-1.32%)	⬇️
...stock/doctype/purchase_receipt/purchase_receipt.py	90.29% <0.00%> (-0.27%)	⬇️
erpnext/stock/get_item_details.py	79.44% <0.00%> (-0.16%)	⬇️
erpnext/stock/reorder_item.py	76.92% <0.00%> (ø)
...ext/payroll/doctype/payroll_entry/payroll_entry.py	71.02% <0.00%> (+0.23%)	⬆️
erpnext/stock/doctype/serial_no/serial_no.py	78.75% <0.00%> (+0.25%)	⬆️
...rpnext/stock/report/stock_balance/stock_balance.py	79.16% <0.00%> (+0.59%)	⬆️
...ype/account/chart_of_accounts/chart_of_accounts.py	77.93% <0.00%> (+0.68%)	⬆️
... and 16 more

[deepeshgarg007]

@Mergifyio backport version-13-hotfix

[mergify]

backport version-13-hotfix

✅ Backports have been created

• #28340 fix(India): Sales Invoice with duplicate items not showing correct taxable value (backport #28334) has been created for branch version-13-hotfix