[Scott Kool (ComradeCow)]

Summary

• Disable Az upgrade checks in the PowerShell launch profile for the current process without changing saved user settings.
• Set container environment variables to disable update notifications for Terraform, GitHub CLI and extensions, npm, pip, and Microsoft 365 CLI.
• Disable .NET workload advertising downloads and Azure CLI Bicep version checks for runtime users.
• Keep the existing PowerShell update-check setting in the Dockerfile and group it with the other settings.
• Add regression coverage for PowerShell and Az update-check settings.

Terraform's Checkpoint setting also disables Checkpoint alerts. Explicit image-build updates remain enabled.

Validation

• PowerShell syntax parsing and git diff --check passed.
• Container tests were not run because the Docker daemon is unavailable.

Resolve #510

[github-actions]

Image size with this change is base: 6186MB, tools: 9855MB.