[CTS] Ensure GoogleTest does not output color

The match files depend on the output from our GoogleTest test suites to
not include ANSI color escape sequences but this setting can be
controlled via environment variable `GTEST_COLOR=yes`. This can cause
tests to fail even though they should not. This patch explicitly
disabled color output by setting `GTEST_COLOR=no` in the test
environment.

Author: kbenzie

test/conformance/CMakeLists.txt

@@ -20,8 +20,12 @@ function(add_test_adapter name adapter)
         WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
     )
 
+    set(testEnv
+        UR_ADAPTERS_FORCE_LOAD="$<TARGET_FILE:ur_${adapter}>"
+        GTEST_COLOR=no
+    )
     set_tests_properties(${TEST_NAME} PROPERTIES
-        ENVIRONMENT "UR_ADAPTERS_FORCE_LOAD=\"$<TARGET_FILE:ur_${adapter}>\""
+        ENVIRONMENT "${testEnv}"
         LABELS "conformance;${adapter}")
 endfunction()