fix(pro:textarea): readonly not working

[sallerli1]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines
• Tests for the changes have been added/updated or not needed
• Docs and demo have been added/updated or not needed

What is the current behavior?

IxProTextarea的readonly不生效

What is the new behavior?

修复以上问题

Other information

[idux-bot]

This preview will be available after the AzureCI is passed.

[codecov]

Codecov Report

Merging #1704 (32d81db) into main (ffd204b) will not change coverage.
The diff coverage is n/a.

❗ Current head 32d81db differs from pull request most recent head 3d7e698. Consider uploading reports for the commit 3d7e698 to get more accurate results

@@           Coverage Diff           @@
##             main    #1704   +/-   ##
=======================================
  Coverage   92.54%   92.54%           
=======================================
  Files         345      345           
  Lines       32421    32421           
  Branches     3693     3693           
=======================================
  Hits        30005    30005           
  Misses       2416     2416