Remove ECR/ACR resource definitions after Docker Hub migration

[ian-flores]

Summary

This is a follow-up to rstudio/ptd#2605 (Migrate to Public Docker Hub). After the migration PR is deployed to all workloads with force_delete=True on ECR/ACR resources, we can safely remove the resource definitions entirely.

Background

In rstudio/ptd#2605, we:

1. Migrated PTD to pull images from public Docker Hub (docker.io/posit/*)
2. Added force_delete=True to ECR repository resources
3. Removed the image copying step from the CLI

This follow-up issue tracks the cleanup of the now-unused ECR/ACR infrastructure.

Tasks

ECR Cleanup (AWS)

• Remove ECR repository definitions from aws_workload_persistent.py
• Remove ECR repository definitions from aws_control_room_persistent.py
• Remove manage_ecr_repositories config field from control room
• Remove shared_resources_read_only ECR-related logic

ACR Cleanup (Azure)

• Review ACR resource handling in azure_workload_persistent.py
• Remove ACR resource definitions if appropriate

Go Code Cleanup

• Remove any remaining references to ECR/ACR image management

Deployment Strategy

1. First: Ensure rstudio/ptd#2605 has been deployed to all workloads
2. Then: Deploy this cleanup PR
   • Pulumi will delete the empty ECR repositories (safe due to force_delete=True)

Files to Modify

• python-pulumi/src/ptd/pulumi_resources/aws_workload_persistent.py
• python-pulumi/src/ptd/pulumi_resources/aws_control_room_persistent.py
• python-pulumi/src/ptd/pulumi_resources/azure_workload_persistent.py

Notes

• ECR repositories should be empty at this point since images are now pulled from Docker Hub
• The force_delete=True flag added in rstudio/ptd#2605 allows deletion even if images remain