[Rule Deprecated] Deprecated - AWS EC2 Snapshot Activity (#4913)

Completing Deprecation process for AWS EC2 Snapshot Activity

- It's been 2 rule releases since initial name change
- changed maturity to deprecation
- updated deprecation_date
- moved file to _deprecated folder

Author: imays11

rules/integrations/aws/exfiltration_ec2_snapshot_change_activity.toml renamed to rules/_deprecated/exfiltration_ec2_snapshot_change_activity.toml

@@ -1,8 +1,9 @@
 [metadata]
 creation_date = "2020/06/24"
 integration = ["aws"]
-maturity = "production"
-updated_date = "2024/06/02"
+maturity = "deprecated"
+updated_date = "2025/07/16"
+deprecation_date = "2025/07/16"
 
 [rule]
 author = ["Elastic"]