Added SSH auth scope to environment

[isra-fel]

To enable updating the auth scope, this PR adds it to the environment. There will be a follow-up PR to update Set-AzEnvironment and logic in SshCredentialFactory in azure-powershell repo.

[Copilot]

Pull Request Overview

Adds SSH authentication scopes to the Azure environment abstraction so that SSH credential logic can pick up the correct resource scope.

• Introduce AzureSshAuthScope (and region-specific variants) in AzureEnvironmentConstants
• Extend ExtendedEndpoint and AzureEnvironmentExtensions.SetEndpoint to handle the new scope
• Populate built-in environments (public, China, USGov) with the SSH auth scope property

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/Authentication.Abstractions/Extensions/AzureEnvironmentExtensions.cs	Handle AzureSshAuthScope in the SetEndpoint switch
src/Authentication.Abstractions/AzureEnvironmentConstants.cs	Define AzureSshAuthScope, ChinaSshAuthScope, USGovernmentSshAuthScope
src/Authentication.Abstractions/AzureEnvironment.cs	Add AzureSshAuthScope member to ExtendedEndpoint
src/Authentication.Abstractions/AzureEnvironment.BuiltIn.cs	Set the new SSH auth scope property on built-in environments

Comments suppressed due to low confidence (2)

src/Authentication.Abstractions/AzureEnvironment.BuiltIn.cs:168

• Add unit tests to verify that the built-in environments for AzureCloud, AzureChinaCloud, and AzureUSGovernment include the new AzureSshAuthScope property with the expected constant values.

azureEnvironments[EnvironmentName.AzureCloud].SetProperty(ExtendedEndpoint.AzureSshAuthScope, AzureEnvironmentConstants.AzureSshAuthScope);

src/Authentication.Abstractions/AzureEnvironmentConstants.cs:299

• The <see> cref references SshCredentialFactory, which may live in a different assembly. Consider qualifying it with its full namespace or removing the tag if it won’t resolve in this project’s documentation build.

/// The scope for SSH authentication. See <see cref="SshCredentialFactory"/>