anv: remove CS_FLUSH from query regression

Fixes performance regression introduced by prior refactoring of
pipe control code that unnecessarily added CS_FLUSH to query start
and end. Issue was diagnosed by Ben L (thank you!)

Confirmed this restores performance on:
* Borderlands3 +2%
* Payday +3%
* Factorio +3%
* HogwartsLegacy +4%
* Ghostrunner +7%

Fixes: 6dc95685 (convert genX_query pipe controls to use pc helper)
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25983>

src/intel/vulkan/genX_query.c

@@ -697,7 +697,7 @@ emit_query_pc_availability(struct anv_cmd_buffer *cmd_buffer,
    genx_batch_emit_pipe_control_write
       (&cmd_buffer->batch, cmd_buffer->device->info,
        cmd_buffer->state.current_pipeline, WriteImmediateData, addr,
-       available, ANV_PIPE_CS_STALL_BIT);
+       available, 0);
 }
 
 /**