make it a warning query

Author: erik-krogh

ql/ql/src/queries/style/UnqueryableCode.ql

@@ -2,7 +2,7 @@
  * @name Unqueryable code
  * @description Code that cannot affect the outcome of any query is suspicous.
  * @kind problem
- * @problem.severity recommendation
+ * @problem.severity warning
  * @id ql/unqueryable-code
  * @precision high
  */
@@ -12,4 +12,4 @@ import codeql_ql.style.DeadCodeQuery
 
 from AstNode node
 where node = unQueryable()
-select node, "Code cannot affect the outcome of any query."
+select node, "Code cannot affect the outcome of any query (including tests)."