mesa: set NewVertexElements when changing IsDynamic

Fixes: 0fbd82bdc4 - mesa: move calling _mesa_update_vao_derived_arrays into st_update_array
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/7938

Acked-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20432>

src/mesa/main/arrayobj.c

@@ -546,6 +546,8 @@ _mesa_update_vao_derived_arrays(struct gl_context *ctx,
    /* More than 4 updates turn the VAO to dynamic. */
    if (ctx->Const.AllowDynamicVAOFastPath && ++vao->NumUpdates > 4) {
       vao->IsDynamic = true;
+      /* IsDynamic changes how vertex elements map to vertex buffers. */
+      ctx->Array.NewVertexElements = true;
       return;
    }