fix(input): readonly prop should only be Boolean

[jizai1125]

readonly: {
   type: [String, Boolean]
}

<!-- parsed as an empty string -> readonly="" -->
<n-input readonly  />

The readonly prop used to accept both String and Boolean, but was parsed as readonly="", which made the clear icon show up.

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
naive-ui	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 10, 2025 7:14am

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 59.28%. Comparing base (c96427d) to head (55e609e).

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6397   +/-   ##
=======================================
  Coverage   59.28%   59.28%           
=======================================
  Files        1149     1149           
  Lines       25434    25434           
  Branches     6412     6412           
=======================================
  Hits        15078    15078           
  Misses       8682     8682           
  Partials     1674     1674           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.