feat: Cookiecutter target tox ini

[mkranna]

Issue #360: target cookiecutter has no tox.ini

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📚 Documentation preview 📚: https://meltano-sdk--1438.org.readthedocs.build/en/1438/

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (main@6ebc5ee). Click here to learn what that means.
The diff coverage is n/a.

❗ Current head e0af5e4 differs from pull request most recent head 39cf40e. Consider uploading reports for the commit 39cf40e to get more accurate results

@@           Coverage Diff           @@
##             main    #1438   +/-   ##
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  Coverage        ?   85.47%           
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  Files           ?       57           
  Lines           ?     4763           
  Branches        ?      808           
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  Hits            ?     4071           
  Misses          ?      501           
  Partials        ?      191           

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[tayloramurphy]

Thanks for the PR @mkranna - we'll have the engineering team take a look and review.

[edgarrmondragon]

Thanks @mkranna!