Fix code style issues in aws-cost function

- Remove trailing spaces
- Fix inconsistent spacing between code blocks
- Ensure proper blank line spacing throughout function
- Maintain consistency with existing codebase style

plugins/aws/aws.plugin.zsh

@@ -256,7 +256,7 @@ function aws-cost() {
     local end_date="$2"
     local granularity="${3:-DAILY}"
 
-    aws ce get-cost-and-usage \
+  aws ce get-cost-and-usage \
       --time-period Start="$start_date",End="$end_date" \
       --granularity "$granularity" \
       --metrics BlendedCost \