Remove policy_scope_toggle_enabled ff checks

What does this MR do and why?

Remove policy_scope_toggle_enabled ff checks

• toggle was removed prior
• removes checks for it
• last MR for Remove feature toggle for security policy scope (#443594 - closed)
• related to Remove security_policies_policy_scope ff (!147977 - merged)

Changelog: removed

EE: true

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Related to #443594 (closed)