Unskip S390 and AIX from nan package

[abhayagarwal-dev]

This PR unskip nan from AIX and S390x.
This was skipped because of endianess issue while decoding UCS2 encoding on Big-Endian platform
The fix is merged with the upstream nan repository.
Issue: nan tests fail on three platforms with Node.js 20.x #996

Fix: fix(test): handle big-endian encoding in EncodeUCS2 test- #1023#1023

The smoke test is passing with the changes

info: starting            | nan                 
info: lookup              | nan                 
info: lookup-found        | nan                 
info: nan lookup-replace  | https://github.com/nodejs/nan/archive/HEAD.tar.gz
info: nan npm:            | Downloading project: https://github.com/nodejs/nan/archive/HEAD.tar.gz
info: nan npm:            | Project downloaded HEAD.tar.gz
info: nan npm:            | npm install started 
warn: nan npm-install:    | npm notice                                                             
warn:                     | npm notice New major version of npm available! 10.2.4 -> 12.1.0        
warn:                     | npm notice Changelog: <https://github.com/npm/cli/releases/tag/v12.1.0>
warn:                     | npm notice Run `npm install -g npm@12.1.0` to update!                  
warn:                     | npm notice                                                             
info: nan npm:            | npm install successfully completed
info: nan npm:            | test suite started  
info: passing module(s)   |                     
info: module name:        | nan                 
info: version:            | 2.29.0              
info: done                | The smoke test has passed.
info: duration            | test duration: 53547ms

Checklist

• npm test passes
• contribution guidelines followed
  here

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.20%. Comparing base (f8ed88e) to head (5e403f5).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1149   +/-   ##
=======================================
  Coverage   96.20%   96.20%           
=======================================
  Files          29       29           
  Lines        2213     2213           
=======================================
  Hits         2129     2129           
  Misses         84       84           

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