ci : enable main-cuda build (#3282)

This commit re-enables the main-cuda Docker build in the CI workflow.
The main-cuda Dockerfile has been updated to remove build artifacts
and also print the size of the /app directory after the build. A similar
change was recently made to the musa Dockerfile, and perhaps this job
was also having similar disk space issues.

The motivation for this change is that this configuration has been
disabled for a while due to persistent build failures. However, the
actual logs are now longer available.

Resolves: https://github.com/ggml-org/whisper.cpp/issues/3040

.devops/main-cuda.Dockerfile

@@ -16,6 +16,7 @@ ENV CUDA_DOCKER_ARCH=${CUDA_DOCKER_ARCH}
 
 RUN apt-get update && \
     apt-get install -y build-essential libsdl2-dev wget cmake git \
+    && apt-get clean \
     && rm -rf /var/lib/apt/lists/* /var/cache/apt/archives/*
 
 # Ref: https://stackoverflow.com/a/53464012
@@ -26,6 +27,12 @@ COPY .. .
 # Enable cuBLAS
 RUN make base.en CMAKE_ARGS="-DGGML_CUDA=1"
 
+RUN find /app/build -name "*.o" -delete && \
+    find /app/build -name "*.a" -delete && \
+    rm -rf /app/build/CMakeFiles && \
+    rm -rf /app/build/cmake_install.cmake && \
+    rm -rf /app/build/_deps
+
 FROM ${BASE_CUDA_RUN_CONTAINER} AS runtime
 ENV CUDA_MAIN_VERSION=12.3
 ENV LD_LIBRARY_PATH /usr/local/cuda-${CUDA_MAIN_VERSION}/compat:$LD_LIBRARY_PATH
@@ -33,8 +40,11 @@ WORKDIR /app
 
 RUN apt-get update && \
   apt-get install -y curl ffmpeg wget cmake git \
+  && apt-get clean \
   && rm -rf /var/lib/apt/lists/* /var/cache/apt/archives/*
 
 COPY --from=build /app /app
+RUN du -sh /app/*
+RUN find /app -type f -size +100M
 ENV PATH=/app/build/bin:$PATH
 ENTRYPOINT [ "bash", "-c" ]

.github/workflows/docker.yml

@@ -20,9 +20,7 @@ jobs:
           - { tag: "main", dockerfile: ".devops/main.Dockerfile", platform: "linux/amd64" }
           - { tag: "main-musa", dockerfile: ".devops/main-musa.Dockerfile", platform: "linux/amd64" }
           - { tag: "main-intel", dockerfile: ".devops/main-intel.Dockerfile", platform: "linux/amd64" }
-          #TODO: the cuda image keeps failing - disable for now
-          #      https://github.com/ggerganov/whisper.cpp/actions/runs/11019444428/job/30602020339
-          #- { tag: "main-cuda", dockerfile: ".devops/main-cuda.Dockerfile", platform: "linux/amd64" }
+          - { tag: "main-cuda", dockerfile: ".devops/main-cuda.Dockerfile", platform: "linux/amd64" }
 
     steps:
       - name: Check out the repo