mesa: flag ST_NEW_FS_CONSTANTS instead of _NEW_PROGRAM for ATI_fs constants

We only need to update the constant buffer.

Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19859>

src/mesa/main/atifragshader.c

@@ -827,7 +827,8 @@ _mesa_SetFragmentShaderConstantATI(GLuint dst, const GLfloat * value)
       curProg->LocalConstDef |= 1 << dstindex;
    }
    else {
-      FLUSH_VERTICES(ctx, _NEW_PROGRAM, 0);
+      FLUSH_VERTICES(ctx, 0, 0);
+      ctx->NewDriverState |= ST_NEW_FS_CONSTANTS;
       COPY_4V(ctx->ATIFragmentShader.GlobalConstants[dstindex], value);
    }
 }