Further clarifying the ref to diff against

Signed-off-by: Luc Berger-Vergiat <[email protected]>

Author: lucbv

scripts/check_api_updates.py

@@ -1,5 +1,5 @@
 from git import Repo
 
 repo = Repo("kokkos-kernels")
-files = repo.git.diff('develop', name_only=True).split()
+files = repo.git.diff('origin/develop', name_only=True).split()
 print(files)