fix: Skip inaccessible CONDA_ENVS_DIRS

[holzman]

Fixes #3848 as well as an adjacent bug if the parent directory is unreadable.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 81.81818% with 2 lines in your changes missing coverage. Please review.

Project coverage is 63.86%. Comparing base (5bc7f9f) to head (9925716).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
libmamba/src/api/configuration.cpp	77.77%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3887   +/-   ##
=======================================
  Coverage   63.86%   63.86%           
=======================================
  Files         300      300           
  Lines       38215    38220    +5     
  Branches     2852     2853    +1     
=======================================
+ Hits        24406    24411    +5     
  Misses      13742    13742           
  Partials       67       67           

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[jjerphan]

LGTM.

@holzman: can you confirm that the changes are still the ones you intended after the merge of main in?

[holzman]

Yes, LGTM