Symlinked paths are excluded from gitignore checks

[ucodery]

No description provided.

[ucodery]

This fixes #1772

[codecov]

Codecov Report

Merging #1773 (2bbf393) into main (191e165) will increase coverage by 0.06%.
The diff coverage is 83.33%.

@@            Coverage Diff             @@
##             main    #1773      +/-   ##
==========================================
+ Coverage   99.89%   99.96%   +0.06%     
==========================================
  Files          37       37              
  Lines        2930     2935       +5     
  Branches      695      697       +2     
==========================================
+ Hits         2927     2934       +7     
+ Misses          2        0       -2     
  Partials        1        1              

[ucodery]

Our company uses a build tool in CI that link a bin dir from the root of the repo to a global private bin dir on the host machine. Before this change, runs of isort had ballooned to a run time of at least 7 minutes. After this change at least 1000 less files were passed to git to check for ignoring and runtime went down to almost 10 seconds.
Also, FYI we have multiple .gitignores at different levels, so a self-contained .gitignore like in #1585 would not have helped.