Updated checks to new PAT format

[max-zaytsev]

Copied from https://github.com/microsoft/azure-pipelines-tasks/pull/20433

Task name: AppCenterTestV1, AzureTestPlanV0

Description: Azure DevOps has implemented a new PAT format that is no longer 52 characters long but 84 characters long with a fixed signature 'AZDO'. To prepare for the transition between the new and old PAT format, I would like to change the PAT checks. We have already changed our documentation on the new PAT format: https://learn.microsoft.com/en-us/azure/devops/organizations/accounts/use-personal-access-tokens-to-authenticate?view=azure-devops&tabs=Windows#changes-to-format

Documentation changes required: (Y/N) N

Added unit tests: (Y/N) N

Attached related issue: (Y/N) N

Checklist:

• [x] Task version was bumped - please check instruction how to do it
• [x] Checked that applied changes work as expected

[martin-toman]

/azp run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 3 pipeline(s).