feat: Add support for azure workload identity in Microsoft Entra SSO.

[jagpreetstamber]

Enables the use of workload identity in configuring Microsoft Entra SSO, removes the secret management overhead for the AAD Apps. CLOSES #17595

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this does not need to be in the release notes. Support Azure Workload Identity for Microsoft Entra SSO #17595
• The title of the PR states what changed and the related issues number (used for the release note).
• The title of the PR conforms to the Toolchain Guide
• I've included "Closes [ISSUE #]" or "Fixes [ISSUE #]" in the description to automatically close the associated issue.
• I've updated both the CLI and UI to expose my feature, or I plan to submit a second PR with them.
• Does this PR require documentation updates?
• I've updated documentation as required by this PR.
• I have signed off all my commits as required by DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My build is green (troubleshooting builds).
• My new feature complies with the feature status guidelines.
• I have added a brief description of why this PR is necessary and/or what this PR solves.
• Optional. My organization is added to USERS.md.
• Optional. For bug fixes, I've indicated what older releases this fix should be cherry-picked into (this may or may not happen depending on risk/complexity).

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[codecov]

Codecov Report

Attention: Patch coverage is 87.12871% with 13 lines in your changes missing coverage. Please review.

Project coverage is 53.29%. Comparing base (1698370) to head (1dd1e65).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
util/oidc/oidc.go	86.53%	5 Missing and 2 partials ⚠️
util/test/testutil.go	86.04%	4 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #21433      +/-   ##
==========================================
- Coverage   55.41%   53.29%   -2.13%     
==========================================
  Files         339      339              
  Lines       57200    57290      +90     
==========================================
- Hits        31700    30532    -1168     
- Misses      22829    24117    +1288     
+ Partials     2671     2641      -30     

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[jagpreetstamber]

Rebased as the code coverage report was incorrect.

[agaudreault]

Made a small refactor to extract getAzureKubernetesFederatedServiceAccountToken to the new struct and updated the unit tests to use a token in a temp test directory.