CrispASR v0.8.29 - macOS Intel (x86_64)

Add a CrispASR macOS Intel (x86_64) build

Upstream's crispasr-macos.tar.gz has been arm64-only since the first
release: the build job runs on macos-latest, which is Apple Silicon since
macos-13 was retired, and sets no CMAKE_OSX_ARCHITECTURES. Intel Macs get
"Bad CPU type in executable", and Rosetta cannot help - it translates
x86_64 to arm64, never the reverse (SubtitleEdit issue #13559).

Cross-compiles the x86_64 slice on the arm64 runner. Metal is off (ggml's
Metal kernels crash on the AMD GPUs in Intel Macs - that is the crash in
the report), native tuning is off so the runner's -mcpu=apple-mN flags
stay out of an x86 compile, the deployment target is pinned so dyld does
not reject the binary on every Mac older than the runner, and the c2pa
sidecar is fetched as x86_64-apple-darwin because CRISPASR_C2PA_FETCH
derives its triple from the host processor.

Verified locally against v0.8.29 on an M-series Mac: x86_64-only binaries,
minos 12.0, ggml backends cpu,blas, no links outside /System and /usr/lib,
and a transcription run under Rosetta.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>