fix: Don't validate FG in repack entry

[marination]

#28555 missed the case of multiple FGs being possible in repack entries.

• An item could repacked into 3/4 smaller items
• In this case 3/4 rows will have is_finished_item auto checked
• This should be allowed in case of repack

Fix:

• The only check for repack should be if theres no row with is_finished_item checked, throw an error
• multiple fg should be allowed

To test:

• case 1: test repack entry with one item consumed and one item created (one has source wh and second row has target)
• case 2: test repack entry with one item consumed and 3 other items created (one item of say 90 qty is repacked into 3 items of 30 qty each)
• Check impact on cost
• Check if is_finished_item checked is checked on the right rows

[codecov]

Codecov Report

Merging #29271 (c49dff3) into develop (82b2d22) will decrease coverage by 0.21%.
The diff coverage is 94.44%.

@@             Coverage Diff             @@
##           develop   #29271      +/-   ##
===========================================
- Coverage    57.96%   57.74%   -0.22%     
===========================================
  Files         1110     1110              
  Lines        68005    68005              
===========================================
- Hits         39420    39271     -149     
- Misses       28585    28734     +149     

Impacted Files	Coverage Δ
erpnext/stock/doctype/stock_entry/stock_entry.py	80.77% <94.44%> (+0.17%)	⬆️
...unts/report/purchase_register/purchase_register.py	32.19% <0.00%> (-41.10%)	⬇️
...tch_item_expiry_status/batch_item_expiry_status.py	69.23% <0.00%> (-25.00%)	⬇️
...wise_balance_history/batch_wise_balance_history.py	68.96% <0.00%> (-24.14%)	⬇️
...ext/accounts/report/balance_sheet/balance_sheet.py	36.36% <0.00%> (-21.82%)	⬇️
...e_purchase_register/item_wise_purchase_register.py	58.00% <0.00%> (-17.00%)	⬇️
...payroll/doctype/income_tax_slab/income_tax_slab.py	83.33% <0.00%> (-16.67%)	⬇️
...it_and_loss_statement/profit_and_loss_statement.py	71.42% <0.00%> (-3.90%)	⬇️
...eport/item_variant_details/item_variant_details.py	84.33% <0.00%> (-3.62%)	⬇️
erpnext/education/doctype/student/student.py	73.68% <0.00%> (-3.16%)	⬇️
... and 27 more

[marination]

@Mergifyio backport version-13-hotfix

[mergify]

backport version-13-hotfix

✅ Backports have been created

• #29274 fix: Don't validate FG in repack entry (backport #29271) has been created for branch version-13-hotfix