feat(terraform): require authentication for workspace subcommands

[moraisph]

Follow-up #581

This PR adds the 'workspace' subcommand to the NeedsAuth list, ensuring it is marked as requiring authentication via 1Password.

Overview

Type of change

• Created a new plugin
• Improved an existing plugin
• Fixed a bug in an existing plugin
• Improved contributor utilities or experience

Related Issue(s)

• Resolves: Add "workspace" subcommand to NeedsAuth in Terraform shell plugin #581

How To Test

1. Ensure the Terraform plugin is configured with credentials provisioned via 1Password.
2. Run the following commands inside a Terraform project:

• terraform workspace list
• terraform workspace select
• terraform workspace new

3. Confirm that each command triggers authentication via 1Password and executes successfully using provisioned credentials.

Changelog

Terraform 'workspace' subcommands trigger authentication via 1Password.