feat: Improve debug logging in retry logic

[majk-p]

Description of changes:

I've got a workflow this action as follows:

  - name: Assume the testing role
    uses: aws-actions/configure-aws-credentials@v4
    with:
      role-to-assume: ${{ inputs.roleToAssume }}
      aws-region: ${{ inputs.targetRegion }}
      aws-access-key-id: ${{ env.AWS_ACCESS_KEY_ID }}
      aws-secret-access-key: ${{ env.AWS_SECRET_ACCESS_KEY }}
      aws-session-token: ${{ env.AWS_SESSION_TOKEN }}
      disable-retry: false
      retry-max-attempts: 30
      role-skip-session-tagging: true
      role-duration-seconds: 3600

I know v5 is the latest, but v4 was the current release until just last week.

Problem
When I change my infrastructure such that the role can no longer be assumed, the action keeps retrying without providing any useful debug information — even when re-running in debug mode:

This PR adds extra debug info to the retry logic to help debugging in a situation like that. It does not alter retry behavior — only adds visibility.

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[kellertk]

Thanks for the contribution!