try clang18 version, see if it fixes crashes

Signed-off-by: Larry Gritz <lg@larrygritz.com>

Author: lgritz

.github/workflows/ci.yml

@@ -685,7 +685,7 @@ jobs:
           - desc: OptiX VP2025 gcc11/C++17 llvm19 py3.11 oiio-rel avx2
             nametag: linux-optix-vfx2025
             runner: ${{ (github.repository_owner == 'AcademySoftwareFoundation' && 'ubuntu-20.04-gpu-t4-4c-16g-176h') || 'ubuntu-latest' }}
-            container: aswf/ci-osl:2025
+            container: aswf/ci-osl:2025-clang18
             container_options: -e NVIDIA_DRIVER_CAPABILITIES=compute,graphics,utility --gpus all
             cxx_std: 17
             python_ver: "3.11"