[cmake] Cleanup.

scripts/cmake/test/AddTestTester.cmake

-set(_exec_process_args "")
-if(${CMAKE_VERSION} VERSION_GREATER_EQUAL 3.18)
-    set(_exec_process_args ECHO_OUTPUT_VARIABLE ECHO_ERROR_VARIABLE)
-endif()
-
 message(STATUS "running tester (glob mode: ${GLOB_MODE}): ${TESTER_COMMAND}")
 
 if(WIN32)
@@ -49,7 +44,7 @@ foreach(cmd ${TESTER_COMMAND})
                 WORKING_DIRECTORY ${SOURCE_PATH}
                 RESULT_VARIABLE EXIT_CODE
                 OUTPUT_VARIABLE OUTPUT
-                ERROR_VARIABLE OUTPUT ${_exec_process_args}
+                ERROR_VARIABLE OUTPUT ECHO_OUTPUT_VARIABLE ECHO_ERROR_VARIABLE
             )
             if(NOT EXIT_CODE STREQUAL "0")
                 file(WRITE ${LOG_FILE} ${OUTPUT})
@@ -67,7 +62,7 @@ foreach(cmd ${TESTER_COMMAND})
             WORKING_DIRECTORY ${SOURCE_PATH}
             RESULT_VARIABLE EXIT_CODE
             OUTPUT_VARIABLE OUTPUT
-            ERROR_VARIABLE OUTPUT ${_exec_process_args}
+            ERROR_VARIABLE OUTPUT ECHO_OUTPUT_VARIABLE ECHO_ERROR_VARIABLE
         )
         if(NOT EXIT_CODE STREQUAL "0")
             file(WRITE ${LOG_FILE} ${OUTPUT})

scripts/cmake/test/NotebookTest.cmake

@@ -75,23 +75,9 @@ function(NotebookTest)
         list(APPEND labels large)
     endif()
 
-    if(MSVC AND ${CMAKE_VERSION} VERSION_LESS 3.22)
-        # ENVIRONMENT_MODIFICATION parameter of set_tests_properties() is
-        # required to correctly set the PATH environment variable on Windows.
-        message(
-            WARNING "Notebook tests are disabled on Windows when CMake < 3.22!"
-        )
-        return()
-    endif()
-
-    if(${CMAKE_VERSION} VERSION_LESS 3.22)
-        # This branch applies to *nix only.
-        set(_prop_env ENVIRONMENT PATH=$<TARGET_FILE_DIR:ogs>:$ENV{PATH})
-    else()
-        set(_prop_env ENVIRONMENT_MODIFICATION
-                      PATH=path_list_prepend:$<TARGET_FILE_DIR:ogs>
-        )
-    endif()
+    set(_prop_env ENVIRONMENT_MODIFICATION
+                  PATH=path_list_prepend:$<TARGET_FILE_DIR:ogs>
+    )
 
     set_tests_properties(
         ${TEST_NAME}