feat: change autothreshold S3 file expiration to 45 days

This is useful for forensics and debugging to retain the models
longer than 1 month as some autothreshold problems can take a long
time to surface.

modules/bigeye/main.tf

@@ -818,7 +818,7 @@ resource "aws_s3_bucket_lifecycle_configuration" "models" {
     id     = "ExpireOldModels"
     status = "Enabled"
     expiration {
-      days = 30
+      days = 45
     }
   }
 }