fix: To reuse Log Analytics across subscriptions

[Vamshi-Microsoft]

Purpose

This pull request introduces a change to the infra/modules/container-app-environment.bicep file to enhance the handling of Log Analytics Workspace scopes. The update ensures that the scope includes the subscription ID extracted from the logAnalyticsResourceId.

Changes related to Log Analytics Workspace scope handling:

• infra/modules/container-app-environment.bicep: Added a variable existingLawSubscription to extract the subscription ID from logAnalyticsResourceId. Updated the scope property of the logAnalyticsWorkspace resource to include both the subscription ID and resource group, improving accuracy in resource targeting.

Does this introduce a breaking change?

• Yes
• No

[Prajwal-Microsoft]

Change the variable name, it might be either existing one or new one