Add CPU (gcc 13, Debug) configuration to CI

I'm seeing issues with later GCC compilers. So let's increase the coverage.

Author: romintomasetti

.github/workflows/ci.cpu.yml

@@ -26,6 +26,7 @@ jobs:
           - { name: "CPU (gcc 11, Release)",         build: "Release", tag: gcc11-cuda12.9,  cxxflags: "", }
           - { name: "CPU (gcc 11, Release, ASAN)",   build: "Release", tag: gcc11-cuda12.9,  cxxflags: "-fsanitize=address" }
           - { name: "CPU (gcc 12, Release, TSAN)",   build: "Release", tag: gcc12-cuda12.9,  cxxflags: "-fsanitize=thread" }
+          - { name: "CPU (gcc 13, Debug)",           build: "Release", tag: gcc13-cuda12.9,  cxxflags: "", }
     container:
       options: -u root
       image: rapidsai/devcontainers:26.02-cpp-${{ matrix.tag }}