Treat the ID token signature validation failure as client error instead of generic error which will be logged as server error later

[sadilchamishka]

Proposed changes in this pull request

In the OIDC logout request, The ID token signature validation failure is not required to be handled as server error and log the error. It should be a client error as the id token is sent by the client apps, along with OIDC logout request.

The failure should have been handled by this exception block [1], but it is being handled from this exception block[2].

[1] - https://github.com/wso2-extensions/identity-inbound-auth-oauth/blob/master/components/org.wso2.carbon.identity.oidc.session/src/main/java/org/wso2/carbon/identity/oidc/session/servlet/OIDCLogoutServlet.java#L244~L251
[2] - https://github.com/wso2-extensions/identity-inbound-auth-oauth/blob/master/components/org.wso2.carbon.identity.oidc.session/src/main/java/org/wso2/carbon/identity/oidc/session/servlet/OIDCLogoutServlet.java#L252~L255

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 55.73%. Comparing base (1eb13c1) to head (d25dd76).

Additional details and impacted files

@@            Coverage Diff            @@
##             master    #2628   +/-   ##
=========================================
  Coverage     55.73%   55.73%           
+ Complexity     8234     8183   -51     
=========================================
  Files           632      632           
  Lines         47478    47478           
  Branches       8385     8385           
=========================================
  Hits          26463    26463           
  Misses        17228    17228           
  Partials       3787     3787           

Flag	Coverage Δ
unit	38.65% <100.00%> (ø)

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[jenkins-is-staging]

PR builder started
Link: https://github.com/wso2/product-is/actions/runs/11897632050

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PR builder completed
Link: https://github.com/wso2/product-is/actions/runs/11897632050
Status: success

[jenkins-is-staging]

Approving the pull request based on the successful pr build https://github.com/wso2/product-is/actions/runs/11897632050

[Thumimku]

Hi @sadilchamishka,

⚠️ Notice: This PR has been open for a while. To keep the repository clean and up-to-date, this PR will be closed within the next two weeks if there is no further activity.

Please take one of the following actions:

• Merge the PR if it is ready.
• Close the PR if it is no longer relevant.
• Leave a comment explaining why it should remain open and provide an update on its progress.

Your prompt attention to this matter is greatly appreciated. Thank you for your understanding and collaboration! 🙏