fix: Multicurrency invoices using subscription

[deepeshgarg007]

The user gets the following error on trying to create an invoice using subscription against a party having billing currency other than the company currency

Sets to test the pull request

1. Create a customer with billing currency other than company currency, Eg USD if company currency is INR

2. Create a subscription plan in party currency
   

3. Create a backdated subscription as per the following details
   

4. Click on the fetch subscription updates button on the top right and see if the invoice gets generated successfully
   

[codecov]

Codecov Report

Merging #28916 (6ab7530) into develop (2be62c2) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff            @@
##           develop   #28916   +/-   ##
========================================
  Coverage    55.57%   55.58%           
========================================
  Files         1126     1126           
  Lines        67199    67201    +2     
========================================
+ Hits         37349    37355    +6     
+ Misses       29850    29846    -4     

Impacted Files	Coverage Δ
...next/accounts/doctype/subscription/subscription.py	81.84% <100.00%> (+0.10%)	⬆️
...work_order_stock_report/work_order_stock_report.py	50.00% <0.00%> (-50.00%)	⬇️
erpnext/assets/doctype/asset/depreciation.py	84.93% <0.00%> (-2.74%)	⬇️
.../report/stock_projected_qty/stock_projected_qty.py	86.84% <0.00%> (-2.64%)	⬇️
...eport/production_analytics/production_analytics.py	69.51% <0.00%> (-1.22%)	⬇️
erpnext/portal/utils.py	28.98% <0.00%> (ø)
...ext/payroll/doctype/payroll_entry/payroll_entry.py	70.79% <0.00%> (ø)
...stock/doctype/purchase_receipt/purchase_receipt.py	90.64% <0.00%> (ø)
erpnext/stock/report/stock_ageing/stock_ageing.py	91.24% <0.00%> (+0.72%)	⬆️
erpnext/stock/reorder_item.py	76.06% <0.00%> (+0.85%)	⬆️
... and 7 more

[deepeshgarg007]

@Mergifyio backport version-13-hotfix

[mergify]

backport version-13-hotfix

✅ Backports have been created

• #28932 fix: Multicurrency invoices using subscription (backport #28916) has been created for branch version-13-hotfix