fix: remove nonexistent CC=clang for Go build step

ROCm 6.1 image doesn't have clang/clang++ in PATH (only amdclang++).
GCC is the default and works fine for CGo linking.

ai/ollama/Dockerfile

@@ -52,10 +52,8 @@ RUN mkdir -p build && cd build && \
     cmake --build . -- -l $(nproc) && \
     cmake --install . --component HIP --strip --prefix /build/dist
 
-# Build the Go binary
+# Build the Go binary (use GCC for CGo linking)
 ENV CGO_ENABLED=1
-ENV CC=clang
-ENV CXX=clang++
 RUN go build -trimpath -o /build/dist/ollama .
 
 # ---------- Runtime image ----------