chore: Remove concrete-core dependecy and use the local concrete-cuda instead

.gitmodules

@@ -2,10 +2,6 @@
 	path = third_party/llvm-project
 	url = git@github.com:zama-ai/concrete-compiler-internal-llvm-project.git
 	shallow = true
-[submodule "compiler/concrete-core"]
-	path = compilers/concrete-compiler/compiler/concrete-core
-	url = git@github.com:zama-ai/concrete-core.git
-	shallow = true
 [submodule "compiler/parameter-curves"]
 	path = compilers/concrete-compiler/compiler/parameter-curves
 	url = git@github.com:zama-ai/parameter-curves.git

compilers/concrete-compiler/compiler/CMakeLists.txt

@@ -125,6 +125,8 @@ add_dependencies(concrete_cpu concrete_cpu_rust)
 # --------------------------------------------------------------------------------
 option(CONCRETELANG_CUDA_SUPPORT "Support Concrete CUDA Execution." OFF)
 
+set(CONCRETE_CUDA_DIR "${CONCRETE_BACKENDS_DIR}/concrete-cuda/implementation")
+
 if(CONCRETELANG_CUDA_SUPPORT)
   if(NOT DEFINED CONCRETE_CORE_PATH)
     message(FATAL_ERROR "Compiling with CUDA support requires setting CONCRETE_CORE_PATH")
@@ -135,8 +137,8 @@ if(CONCRETELANG_CUDA_SUPPORT)
   message(STATUS "Found CUDA version: ${CUDAToolkit_VERSION}")
   message(STATUS "Found CUDA library dir: ${CUDAToolkit_LIBRARY_DIR}")
   link_directories(${CUDAToolkit_LIBRARY_DIR})
-  add_subdirectory(${CONCRETE_CORE_PATH}/concrete-cuda/cuda)
-  include_directories(${CONCRETE_CORE_PATH}/concrete-cuda/cuda/include)
+  add_subdirectory(${CONCRETE_CUDA_DIR} concrete-cuda)
+  include_directories(${CONCRETE_CUDA_DIR}/include)
   include_directories(${CUDAToolkit_INCLUDE_DIRS})
   add_compile_options(-DCONCRETELANG_CUDA_SUPPORT)
 endif()