feat: drop support for terraform v1.8

[jooola]

Removes support for terraform v1.8

See https://endoflife.date/terraform

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 30.60%. Comparing base (faa3ddb) to head (81c7a8a).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1066   +/-   ##
=======================================
  Coverage   30.60%   30.60%           
=======================================
  Files          66       66           
  Lines        9942     9942           
=======================================
  Hits         3043     3043           
  Misses       6859     6859           
  Partials       40       40           

Flag	Coverage Δ
unit	30.60% <ø> (ø)

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[lukasmetzner]

Any reason why we keeping 1.7 though?

[jooola]

Any reason why we keeping 1.7 though?

1.7 is the opentofu version :)