lib: fix readdir in recursive mode with a buffer argument

[y-okt]

Fixes: #58892

Calling readdir with a Buffer argument and the recursive flag produces an ERR_INVALID_ARG_TYPE error. The expected behavior would be for the readdir functions not to error and return either an array of Buffers or Dirents (depending on options.withFileTypes)

[codecov]

Codecov Report

❌ Patch coverage is 96.61017% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.51%. Comparing base (6432765) to head (373b9a5).
⚠️ Report is 10 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/fs/promises.js	93.10%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #60936   +/-   ##
=======================================
  Coverage   88.51%   88.51%           
=======================================
  Files         703      703           
  Lines      208396   208446   +50     
  Branches    40201    40208    +7     
=======================================
+ Hits       184460   184513   +53     
- Misses      15939    15940    +1     
+ Partials     7997     7993    -4     

Files with missing lines	Coverage Δ
lib/fs.js	98.20% <100.00%> (+0.01%)	⬆️
lib/internal/fs/promises.js	98.03% <93.10%> (-0.12%)	⬇️

... and 31 files with indirect coverage changes

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