docs: add note about pod identity deprecation

[aramase]

Signed-off-by: Anish Ramasekar anish.ramasekar@gmail.com

Reason for Change:

• AAD Pod Identity has been deprecated. AKV provider for Secrets Store CSI Driver supports workload identity with Azure AD Apps and managed identity, so that's the recommended identity access mode.

Requirements

• squashed commits
• included documentation
• added unit tests and e2e tests (if applicable).

Issue Fixed:

Does this change contain code from or inspired by another project?

• Yes
• No

If "Yes," did you notify that project's maintainers and provide attribution?

Special Notes for Reviewers:

[codecov-commenter]

Codecov Report

Merging #1018 (adddf70) into master (384c8e7) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1018   +/-   ##
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  Coverage   58.91%   58.91%           
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  Files          10       10           
  Lines        1066     1066           
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  Hits          628      628           
  Misses        403      403           
  Partials       35       35