[Bug][ci] : Cling 1.3 ci difference between root and CppInterOps ci

[mcbarton]

Description of bug

In the PR which dropped llvm 18 support (#785) several tests had to be skipped on Windows when updating to cling 1.3 (see comment here #785 (comment)). These tests do not fail on Roots ci, so some difference between the ci in Root and CppInterOp is causing them to fail and needs investigating.