Thank you. Setting this environment helped to remove the first error message

export ANV_VIDEO_DECODE=1
vulkaninfo | grep VK_KHR_video_decode_queue
    VK_KHR_video_decode_queue                     : extension revision 8

Still remaining hwaccel initialisation returned error for h264 and h265 input respectively:

Same for me (with AMD)

export ANV_VIDEO_ENCODE=1
vulkaninfo | grep VK_KHR_video
    VK_KHR_video_decode_h264                      : extension revision 9
    VK_KHR_video_decode_h265                      : extension revision 8
    VK_KHR_video_decode_queue                     : extension revision 8
    VK_KHR_video_queue                            : extension revision 8