zink: disable bindless texture ext with descriptor buffer

it's illegal to mix-and-match DB and non-DB descriptor usage, so disable
this until I finish the implementation

cc: mesa-stable

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20912>

src/gallium/drivers/zink/zink_screen.c

@@ -773,7 +773,7 @@ zink_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
       return 1;
 
    case PIPE_CAP_BINDLESS_TEXTURE:
-      return screen->info.have_EXT_descriptor_indexing;
+      return zink_descriptor_mode != ZINK_DESCRIPTOR_MODE_DB && screen->info.have_EXT_descriptor_indexing;
 
    case PIPE_CAP_TEXTURE_BUFFER_OFFSET_ALIGNMENT:
       return screen->info.props.limits.minTexelBufferOffsetAlignment;