fix(ci): Use correct ENV value for production

[khvn26]

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Changes

This provides correct ENV value to E2E tests ran against production.

How did you test this code?

This is a CI change.

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3 Ignored Deployments

Name	Status	Preview	Comments	Updated (UTC)
docs	⬜️ Ignored (Inspect)			Jun 25, 2024 8:32pm
flagsmith-frontend-preview	⬜️ Ignored (Inspect)			Jun 25, 2024 8:32pm
flagsmith-frontend-staging	⬜️ Ignored (Inspect)			Jun 25, 2024 8:32pm

[github-actions]

Uffizzi Preview deployment-53497 was deleted.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.57%. Comparing base (a3bae58) to head (8c52f51).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4237   +/-   ##
=======================================
  Coverage   96.57%   96.57%           
=======================================
  Files        1190     1190           
  Lines       38754    38754           
=======================================
  Hits        37426    37426           
  Misses       1328     1328           

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