Tests/RunCMake: Tell cmake not to report unused command-line options

On OS X we pass -DCMAKE_POLICY_DEFAULT_CMP0025=NEW to all tests.
Once tests start using cmake_minimum_required(VERSION 3.0) then
CMake will warn that CMAKE_POLICY_DEFAULT_CMP0025 is unused.
These warnings are not part of the expected test output and can
cause such tests to fail.  Pass --no-warn-unused-cli to each test
cmake invocation to tell it not to produce these warnings.
Merge topic 'tests-RunCMake-no-unused' into next

7cd239ed Tests/RunCMake: Tell cmake not to report unused command-line options