Pass CLI auth to Python mutator subprocess

[varundeepsaini]

Closes #4131

Changes

Pass authentication environment variables to the Python mutator subprocess, allowing WorkspaceClient() to function without explicit authentication configuration.

Why

Fixes issue where Python mutators couldn't use WorkspaceClient() without manually passing auth arguments. The CLI now passes DATABRICKS_HOST, DATABRICKS_TOKEN, and other environment variables to the Python subprocess.

Tests

• Unit test verifying auth env vars are passed to subprocess
• Acceptance test (bundle/python/workspace-client-auth) that creates a WorkspaceClient() and calls current_user.me()

[github-actions]

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Trigger:
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Inputs:

• PR number: 4172
• Commit SHA: 0938a25a97727eee7c69a26efcc61dbc418070bf

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