Don't always skip objc/objc++ tests on Windows

These tests can run under MSYS2 using gcc or clang objc/objc++.

run_project_tests.py

@@ -565,8 +565,8 @@ def detect_tests_to_run():
         ('vala', 'vala', backend is not Backend.ninja or not shutil.which('valac')),
         ('rust', 'rust', backend is not Backend.ninja or not shutil.which('rustc')),
         ('d', 'd', backend is not Backend.ninja or not have_d_compiler()),
-        ('objective c', 'objc', backend not in (Backend.ninja, Backend.xcode) or mesonlib.is_windows() or not have_objc_compiler()),
-        ('objective c++', 'objcpp', backend not in (Backend.ninja, Backend.xcode) or mesonlib.is_windows() or not have_objcpp_compiler()),
+        ('objective c', 'objc', backend not in (Backend.ninja, Backend.xcode) or not have_objc_compiler()),
+        ('objective c++', 'objcpp', backend not in (Backend.ninja, Backend.xcode) or not have_objcpp_compiler()),
         ('fortran', 'fortran', backend is not Backend.ninja or not shutil.which('gfortran')),
         ('swift', 'swift', backend not in (Backend.ninja, Backend.xcode) or not shutil.which('swiftc')),
         ('cuda', 'cuda', backend not in (Backend.ninja, Backend.xcode) or not shutil.which('nvcc')),