Default builds no longer pull onnxruntime: conan enable_onnx and the conan
profiles default to False, meson enable-onnx defaults to disabled and skips
onnxruntime discovery entirely, and setup.sh/setup.ps1 only enable ONNX
(and the ONNX-backed Glint plugin) with --with-onnx / -WithOnnx.
YAMS_DISABLE_ONNX=true still forces it off.
This removes a build blocker on hosts where conan tries to build
onnxruntime from source (e.g. ROCm/MIGraphX on Linux). Release, Docker, and
Arch packaging pass the flag explicitly, so shipped artifacts are unchanged
until ONNX is dropped.
faiss requires OpenMP which Apple Clang does not ship. Skip faiss
on macOS/apple-clang to prevent conan install failures during warm.
Also restore trailing whitespace in Linux gcc profiles to match
original cache key hash (hashFiles change invalidated all platform
caches, exposing the macOS issue).
tools.build:compiler_executables requires bare executable names, not
'ccache clang' with a space. setup.sh already wraps CC/CXX with ccache
for Meson builds. The warm step's meson compile (Fix 3) populates
ccache for YAMS source. Conan dep ccache will be addressed separately.
