cmake, test: Disable tests instead of ignoring them

cmake/tests.cmake

@@ -2,8 +2,9 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or https://opensource.org/license/mit/.
 
-if(TARGET Python3::Interpreter)
+add_test(NAME util_rpcauth_test
-  add_test(NAME util_rpcauth_test
   COMMAND Python3::Interpreter ${PROJECT_BINARY_DIR}/test/util/rpcauth-test.py
-  )
+)
-endif()
+set_tests_properties(util_rpcauth_test PROPERTIES
+  DISABLED $<NOT:$<TARGET_EXISTS:Python3::Interpreter>>
+)