fix(build): link the split ggml archives with static whisper

[naanlizard]

The below is Claude-written (as is the change). Manually tested/reproduced by me

Reproduction

On current master, in a fresh build directory:

cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release -DOME_BUILD_TESTS=ON
cmake --build build

The test binaries fail to link (excerpt):

/usr/bin/ld: /opt/ovenmediaengine/lib/libwhisper.a(whisper.cpp.o): in function `whisper_full_with_state':
whisper.cpp:(.text+0x293f3): undefined reference to `ggml_backend_buffer_free'
/usr/bin/ld: whisper.cpp:(.text+0x299bc): undefined reference to `ggml_time_us'
/usr/bin/ld: /opt/ovenmediaengine/lib/libwhisper.a(whisper.cpp.o): in function `whisper_log_set':
whisper.cpp:(.text+0x102d1): undefined reference to `ggml_log_set'
/usr/bin/ld: /opt/ovenmediaengine/lib/libwhisper.a(whisper.cpp.o): in function `whisper_vad_init_with_params::{lambda(vad_tensor, ggml_tensor*)#2}::operator()(vad_tensor, ggml_tensor*) const [clone .cold]':
whisper.cpp:(.text.unlikely+0x81e): undefined reference to `ggml_free'
clang: error: linker command failed with exit code 1

Cause

Release builds use static whisper (OME_WHISPER_STATIC defaults to ON for Release), and whisper.cpp ships ggml as three static archives: libggml.a, libggml-base.a, libggml-cpu.a. The build only tells the linker about ggml-cpu. The other two do appear on the link line (via whisper.pc), but before libwhisper.a. A static archive placed before the code that uses it does not resolve anything.

The main OvenMediaEngine binary links anyway, by luck: third_parties.cpp calls two ggml functions directly, which makes the linker pull in the right archives early. Any other binary that links whisper, such as the test binaries, fails.

Fix

Add all three ggml archives to the link line again, after libwhisper.a, where the linker can actually use them. Shared-whisper builds are unaffected.