fix(data): remove incorrect Clang support for P0288

The entry for std::move_only_function (P0288) is removed for Clang because 
libc++ has not yet implemented this feature (ref: LLVM PR #94670). The previous 
"Supported" status was likely a false positive result from testing Clang with 
the GNU libstdc++ backend on Linux.

Signed-off-by: raycppwizard <232825042+raycppwizard@users.noreply.github.com>

Author: raycppwizard

features_cpp23.yaml

@@ -526,7 +526,6 @@ features:
     lib: true
     support:
       - GCC 12
-      - Clang 17
       - MSVC 14.32
     ftm:
       - name: __cpp_lib_move_only_function