[6.1] Add CodeQL suppression for DefaultAzureCredential and fix macOS CI failures

[paulmedynski]

Port of #3542.

• Adjusted CodeQL suppression to meet the strict requirements of where it may appear relative to the flagged code.
• Adding catch for macOS socket error to log and ignore.

[Copilot]

Pull Request Overview

This PR ports changes from PR #3542 to the 6.1 branch, focusing on CodeQL suppression compliance and macOS CI stability. The changes address static analysis requirements and handle platform-specific socket errors.

• Added proper CodeQL suppression with detailed justification for DefaultAzureCredential instantiation
• Enhanced error handling for socket timeout operations on macOS with logging
• Improved code structure by extracting constant and adding exception handling

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
ActiveDirectoryAuthenticationProvider.cs	Added CodeQL suppression with justification and restructured DefaultAzureCredential instantiation
SniTcpHandle.netcore.cs	Added try-catch block for socket timeout reset with macOS-specific error handling and logging

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.82%. Comparing base (70d54d1) to head (f156064).
⚠️ Report is 3 commits behind head on release/6.1.

Additional details and impacted files

@@               Coverage Diff                @@
##           release/6.1    #3550       +/-   ##
================================================
+ Coverage        66.03%   90.82%   +24.79%     
================================================
  Files              281        6      -275     
  Lines            62401      316    -62085     
================================================
- Hits             41205      287    -40918     
+ Misses           21196       29    -21167     

Flag	Coverage Δ
addons	90.82% <ø> (ø)
netcore	?
netfx	?

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