CI: fix release build (Ubuntu)

PR ggml-org#8006 changes defaults to build shared libs. However, CI for release
builds expects static builds.

Author: loonerin

.github/workflows/build.yml

@@ -222,7 +222,7 @@ jobs:
         run: |
           mkdir build
           cd build
-          cmake .. -DLLAMA_FATAL_WARNINGS=ON -DLLAMA_CURL=ON
+          cmake .. -DLLAMA_FATAL_WARNINGS=ON -DLLAMA_CURL=ON -DBUILD_SHARED_LIBS=OFF
           cmake --build . --config Release -j $(nproc)
 
       - name: Test