add delete session

sqlite/query.sql

@@ -90,6 +90,9 @@ WHERE id = ?;
 -- name: CreateNewSession :exec
 INSERT INTO user_sessions (id, user_id, created_at) VALUES (?, ?, ?);
 
+-- name: DeleteSession :exec
+DELETE FROM user_sessions WHERE id = ?;
+
 -- name: GetSession :one
 SELECT id, user_id, created_at FROM user_sessions WHERE user_id = ?;