fix: service account authentication and ignore yarn config from environment variables

[v-viyada]

Details

This PR adjust the logic to set yarn config before installing runtime dependencies. It filters out environment variables starting with yarn_. This is to make Yarn commands for ado extension independent of any environment setting and if environment variable contains invalid/unrecognized variable starting with yarn_ than it throughs error. For example, environment YARN_MIN_VERSION (This is no valid config in yarn 3) will give below error:
Unrecognized or legacy configuration settings found: minVersion - run "yarn config -v" to see the list of settings supported in Yarn (in )

Also it updates accessibility insights scan package to fix the issue #2182.

Motivation

Context

Pull request checklist

• Addresses an existing issue: Fixes [Bug] service account authentication failure for crawling urls #2569 #2182
• Added relevant unit test for your changes. (yarn test)
• Verified code coverage for the changes made. Check coverage report at: <rootDir>/test-results/unit/coverage
• Ran precheckin (yarn precheckin)

[madalynrose]

Closing and re-opening immediately to hopefully fetch license status properly.

[DragosDanielBoia]

@microsoft-github-policy-service agree