Add Buyer Tax ID (GSTIN) column to India sales report

[Devwill2]

Fixes: #2183

Summary

Changes: Modified report job to include GSTIN field and removed filter that excluded B2B purchases, now showing all India sales with their tax IDs.

Ai Discolsure

None. All code written by me

Livestream Viewing Confirmation

Have watched both the live streams end-to-end

ScreenShot

[Devwill2]

https://github.com/antiwork/gumroad/actions/runs/20343523153/job/58449875296?pr=2186#step:8:83 The failing tests appear to be unrelated to the changes in this PR. Thanks