Remove duplicated example in IntoBytes::write_to_suffix

[ojeda]

Commit b964747 ("Improve AsBytes documentation (#660)") added examples but one of those (IntoBytes::write_to_suffix) has duplicated lines, i.e. the Err case is explained below.

Thus remove them.

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.85%. Comparing base (f70e422) to head (5e03e66).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3422      +/-   ##
==========================================
- Coverage   91.85%   91.85%   -0.01%     
==========================================
  Files          20       20              
  Lines        6093     6089       -4     
==========================================
- Hits         5597     5593       -4     
  Misses        496      496              

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[joshlf]

Once #3423 merges, we can re-run CI tests here and they should pass.

[joshlf]

Oh also, @ojeda you'll need to sign the CLA – alternatively we can just re-upload this for you, which also works.