Reflect dependency on patchelf in README

[f3flight]

Subj, from the readme it's not obvious that a separate non-automatically installed dependency is required, so I think we need to update the text.

[codecov]

Codecov Report

Merging #355 (54785e6) into main (cc1273c) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #355   +/-   ##
=======================================
  Coverage   92.35%   92.35%           
=======================================
  Files          23       23           
  Lines        1256     1256           
  Branches      307      307           
=======================================
  Hits         1160     1160           
  Misses         55       55           
  Partials       41       41           

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