Add clang to the main Ubuntu 22.04 machine (#130)

This commit adds clang to the main Ubuntu 22.04 machine as an optional
compiler; with that, the dedicated Ubuntu 22.04 clang machine becomes
obsolete.

.github/workflows/build-images.yml

@@ -21,7 +21,6 @@ jobs:
           - ubuntu2204
           - ubuntu2204_cuda
           - ubuntu2204_cuda_oneapi
-          - ubuntu2204_clang
           - ubuntu2204_rocm_clang
           - ubuntu2204_rocm_clang_cxx20
           - ubuntu2404

ubuntu2204/Dockerfile

@@ -44,6 +44,7 @@ RUN apt-get update -y \
     ccache \
     libsqlite3-dev \
     time \
+    clang \
   && apt-get clean -y
 
 # manual builds for hep-specific packages
@@ -69,3 +70,6 @@ RUN git clone https://github.com/microsoft/onnxruntime src \
     --allow_running_as_root \
   && cmake --build build/MinSizeRel -- install \
   && rm -rf build src
+
+ENV CC gcc
+ENV CXX g++