fix: extractall for rar-files did not extract anything

[kingjan1999]

This fixes an issue with extractall in the RAR adapter. ATM, when passing None to members, the adapter in turn passes an empty set to the rarfile module, so nothing is extracted.

This hasn't been caught in the tests because of a typo.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (e30907a) to head (2cebfd4).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main        #8   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           11        11           
  Lines          703       704    +1     
=========================================
+ Hits           703       704    +1     

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[Ravencentric]

Looks good to me, thank you.