Fix #4471 : Remove the discuss link from the UI

[PrasadCodesML]

This PR removes the "Discuss" link as mentioned in the issue #4471 from multiple header components in accordance with the project guidelines.

The changes include:

1. Removing the "Discuss" link from main-header.html (mobile demo).
2. Removing the "Discuss" link from sim-header.html.
3. Removing the "Discuss" link from header-static.component.html.

These modifications ensure consistency across different headers while adhering to the design and functionality requirements.

Changes:

1. main-header.html: Removed "Discuss" link.
2. sim-header.html: Removed "Discuss" link.
3. header-static.component.html: Removed "Discuss" link.

Screenshot :

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 69.30%. Comparing base (96968d6) to head (9fe0749).
Report is 1115 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4472      +/-   ##
==========================================
- Coverage   72.93%   69.30%   -3.63%     
==========================================
  Files          83       20      -63     
  Lines        5368     3574    -1794     
==========================================
- Hits         3915     2477    -1438     
+ Misses       1453     1097     -356     

see 64 files with indirect coverage changes

see 64 files with indirect coverage changes

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[RishabhJain2018]

Thanks for the PR. LGTM!