[ci] Use unversioned clang/clang++.

Author: ChrisCummins

.github/actions/install-cmake-build-dependencies/action.yaml

@@ -12,8 +12,10 @@ runs:
                   brew install bazelisk ccache cmake zlib
               else
                   # Compiler
-                  sudo apt-get install clang++-9 lld-9 tar bzip2 ninja-build
-                  sudo apt-get install tar bzip2 ninja-build
+                  sudo apt-get install -y bzip2 clang-9 clang++-9 lld-9 tar bzip2 ninja-build tar ninja-build
+                  sudo ln -s $(which clang++-9) /usr/bin/clang++
+                  sudo ln -s $(which clang-9) /usr/bin/clang
+                  sudo ln -s $(which lld-9) /usr/bin/lld
                   # CMake
                   wget https://github.com/Kitware/CMake/releases/download/v3.20.5/cmake-3.20.5-linux-x86_64.sh -O /tmp/cmake.sh
                   sudo bash /tmp/cmake.sh --prefix=/usr/local --exclude-subdir --skip-license

.github/workflows/ci.yaml

@@ -56,8 +56,8 @@ jobs:
               run: |
                   cmake \
                       -GNinja \
-                      -DCMAKE_C_COMPILER=clang-9 \
-                      -DCMAKE_CXX_COMPILER=clang++-9 \
+                      -DCMAKE_C_COMPILER=clang \
+                      -DCMAKE_CXX_COMPILER=clang++ \
                       -DCMAKE_EXE_LINKER_FLAGS_INIT="-fuse-ld=lld" \
                       -DCMAKE_MODULE_LINKER_FLAGS_INIT="-fuse-ld=lld" \
                       -DCMAKE_SHARED_LINKER_FLAGS_INIT="-fuse-ld=lld" \