Restrict LuxTestUtils to v1

The GNNLux tests currently fail because of breaking changes in LuxTestUtils v2 (or so it seems from a casual look). Until someone has time to upgrade the GNNLux tests, I propose setting a compat bound in order to see if anything is truly broken.

Author: simsurace

GNNLux/test/Project.toml

@@ -20,3 +20,6 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 TestItemRunner = "f8b46487-2199-4994-9208-9a1283c18c0a"
 TestItems = "1c621080-faea-4a02-84b6-bbd5e436b8fe"
 Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
+
+[compat]
+LuxTestUtils = "1"