Hide edit pencil from accessibility

[bmarty]

Content

Ensure that the unlabelled pencil icon is not focusable by the screen reader. This can be not focusable since the click action is the same than the avatar itself.

Motivation and context

Closes #6378

Screenshots / GIFs

Before	After

After the pencil icon is not focusable.

Tests

• Enable screenreader
• start a room creation
• add an avatar picture
• focus on the avatar
• see that the pencil icon is not focusable anymore.

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• This PR was made with the help of AI:
  • Yes. In this case, please request a review by Copilot.
  • No.
• Changes have been tested on an Android device or Android emulator with API 24
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request title will be used in the release note, it clearly defines what will change for the user
• Pull request includes screenshots or videos if containing UI changes
• You've made a self review of your PR

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.26%. Comparing base (64d9336) to head (67c6689).

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #6826   +/-   ##
========================================
  Coverage    81.26%   81.26%           
========================================
  Files         2648     2648           
  Lines        74171    74173    +2     
  Branches      9622     9622           
========================================
+ Hits         60278    60280    +2     
  Misses       10341    10341           
  Partials      3552     3552           

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[jmartinesp]

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