fix: calculate taxes after mapping

[Ninad1306]

When enabling the Auto Create Purchase Receipt, the GST is not being automatically calculated, requiring manual entry of the purchase taxes and charges.

_{Huly®: IC-2794}

[codecov]

Codecov Report

Attention: Patch coverage is 38.46154% with 8 lines in your changes missing coverage. Please review.

Project coverage is 61.31%. Comparing base (4bb9af2) to head (f5bed26).

Files with missing lines	Patch %	Lines
...compliance/gst_india/overrides/purchase_receipt.py	38.46%	8 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2670      +/-   ##
===========================================
- Coverage    61.33%   61.31%   -0.03%     
===========================================
  Files          119      119              
  Lines        11505    11518      +13     
===========================================
+ Hits          7057     7062       +5     
- Misses        4448     4456       +8     

Files with missing lines	Coverage Δ
india_compliance/hooks.py	100.00% <ø> (ø)
...compliance/gst_india/overrides/purchase_receipt.py	64.28% <38.46%> (-22.39%)	⬇️

[vorasmit]

This fix may be needed in ERPNext.