Add an apply Rails/CompactBlank rubocop rule

In rubocop-rails 2.26.0, the Rails/CompactBlank rule was modified to handle
cases where select(&:present?) is used. After identifying three occurrences
in our code, we've decided to apply this rule as it encourages the use of the
more efficient and clearer method, compact_blank.

By using compact_blank, we improve code clarity and performance, as this method performs the same operation but in a more optimized way.

.rubocop.yml

@@ -367,6 +367,9 @@ Rails/ActiveRecordCallbacksOrder:
 Rails/AddColumnIndex:
   Enabled: true
 
+Rails/CompactBlank:
+  Enabled: true
+
 Rails/CreateTableWithTimestamps:
   Enabled: true
   Exclude: