Add .npmrc to .gitignore to fix publish workflow

[asabaylus]

The NPM publish workflow creates a .npmrc file for authentication,
which was causing the 'auto shipit' command to fail with "Working
directory is not clean" error. Adding .npmrc to .gitignore resolves
this issue.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (7af34df) to head (1a6fdcd).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main     #1613   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            7         7           
  Lines          238       238           
  Branches        47        47           
=========================================
  Hits           238       238           

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