[FIX] Add missing InGroup to warning introduced as part of D71830

Author: jdoerfert

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -9912,7 +9912,8 @@ def err_omp_declare_variant_incompat_attributes : Error<
   "'#pragma omp declare variant' is not compatible with any target-specific attributes">;
 def warn_omp_declare_variant_score_not_constant
     : Warning<"score expressions in the OpenMP context selector need to be "
-              "constant; %0 is not and will be ignored">;
+              "constant; %0 is not and will be ignored">,
+      InGroup<SourceUsesOpenMP>;
 def err_omp_declare_variant_user_condition_not_constant
     : Error<"the user condition in the OpenMP context selector needs to be "
             "constant; %0 is not">;