Disable downloads during test, and leave it to portage.

Ultimately the to be downloaded matrices should be in DISTFILES.

Index: hipSPARSE-rocm-5.7.1/clients/tests/CMakeLists.txt
===================================================================
--- hipSPARSE-rocm-5.7.1.orig/clients/tests/CMakeLists.txt
+++ hipSPARSE-rocm-5.7.1/clients/tests/CMakeLists.txt
@@ -24,40 +24,6 @@
 find_package(GTest REQUIRED)
 
 
-#
-# Client matrices.
-#
-if(NOT EXISTS "${CMAKE_MATRICES_DIR}")
-  #
-  # Download.
-  #
-  set(CMAKE_MATRICES_DIR ${PROJECT_BINARY_DIR}/matrices CACHE STRING "Matrices directory.")
-  file(MAKE_DIRECTORY ${CMAKE_MATRICES_DIR})
-
-  if(NOT TARGET hipsparse)
-    set(CONVERT_SOURCE ${CMAKE_SOURCE_DIR}/../deps/convert.cpp CACHE STRING "Convert tool mtx2csr.")
-    include(${CMAKE_SOURCE_DIR}/../cmake/ClientMatrices.cmake)
-  else()
-   set(CONVERT_SOURCE ${CMAKE_SOURCE_DIR}/deps/convert.cpp CACHE STRING "Convert tool mtx2csr.")
-    include(${CMAKE_SOURCE_DIR}/cmake/ClientMatrices.cmake)
-  endif()
-
-else()
-  #
-  # Copy.
-  #
-  if(NOT CMAKE_MATRICES_DIR STREQUAL "${PROJECT_BINARY_DIR}/matrices")
-    message("Copy matrix files from ${CMAKE_MATRICES_DIR} to ${PROJECT_BINARY_DIR}/matrices")
-
-    execute_process(COMMAND cp -r ${CMAKE_MATRICES_DIR} ${PROJECT_BINARY_DIR}/matrices RESULT_VARIABLE STATUS WORKING_DIRECTORY ${CMAKE_MATRICES_DIR})
-
-    if(STATUS AND NOT STATUS EQUAL 0)
-      message(FATAL_ERROR "Failed to copy matrix .bin files, aborting.")
-    endif()
-  endif()
-
-endif()
-
 set(HIPSPARSE_TEST_SOURCES
   hipsparse_gtest_main.cpp
   test_axpyi.cpp