Respect CMAKE_CUDA_ARCHITECTURES, so they can be set by the user in the triplet file.

Also make the CUDA warnings fatal since we are always strictly enabling/disabling CUDA.

--- a/SuiteSparse_config/cmake_modules/SuiteSparsePolicy.cmake
+++ b/SuiteSparse_config/cmake_modules/SuiteSparsePolicy.cmake
@@ -321,7 +321,7 @@
 if ( SUITESPARSE_USE_CUDA )
 
     # try finding CUDA
-    check_language ( CUDA )
+    enable_language ( CUDA )
     # message ( STATUS "Looking for CUDA" )
     if ( CMAKE_CUDA_COMPILER )
         # with CUDA:
@@ -334,7 +334,7 @@
         message ( STATUS "CUDA toolkit lib: " ${CUDAToolkit_LIBRARY_DIR} )
         if ( CUDAToolkit_VERSION VERSION_LESS "11.2" )
             # CUDA is present but too old
-            message ( STATUS "CUDA:               not enabled (CUDA 11.2 or later required)" )
+            message ( FATAL_ERROR "CUDA 11.2 or later is required" )
             set ( SUITESPARSE_HAS_CUDA OFF )
         else ( )
             # CUDA 11.2 or later present
@@ -343,7 +343,7 @@
         endif ( )
     else ( )
         # without CUDA:
-        message ( STATUS "CUDA:             not found" )
+        message ( FATAL_ERROR "CUDA not found" )
         set ( SUITESPARSE_HAS_CUDA OFF )
     endif ( )
 
@@ -354,13 +354,6 @@
 
 endif ( )
 
-if ( SUITESPARSE_HAS_CUDA )
-    message ( STATUS "CUDA:             enabled" )
-    set ( SUITESPARSE_CUDA_ARCHITECTURES "52;75;80" CACHE STRING "CUDA architectures" )
-    set ( CMAKE_CUDA_ARCHITECTURES ${SUITESPARSE_CUDA_ARCHITECTURES} )
-else ( )
-    message ( STATUS "CUDA:             not enabled" )
-endif ( )
 
 # check for strict usage
 if ( SUITESPARSE_USE_STRICT AND SUITESPARSE_USE_CUDA AND NOT SUITESPARSE_HAS_CUDA )