Remove table_exists? check that became unnecessary after rails#43009

Co-authored-by: Haroon Ahmed <[email protected]>

Author: jorgemanrubia

activerecord/lib/active_record/encryption/encryptable_record.rb

@@ -133,7 +133,7 @@ def add_length_validation_for_encrypted_columns
           end
 
           def validate_column_size(attribute_name)
-            if table_exists? && limit = columns_hash[attribute_name.to_s]&.limit
+            if limit = columns_hash[attribute_name.to_s]&.limit
               validates_length_of attribute_name, maximum: limit
             end
           end