feat(arm): add CKV_AZURE_73 to ensure that Automation account variables are encrypted

[userrut]

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feat(arm): add CKV_AZURE_73 to ensure that Automation account variables are encrypted

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Description

This change introduces the CKV_AZURE_73 validation to verify encryption of all variables within the Azure Automation account. By implementing this check, we guarantee the protection and encryption of sensitive information stored in these variables.

Fixes # (issue)

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Fix

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