Use VA encoders hardware acceleration

[kdwk]

System Info

• io.github.seadve.Kooha 2.2.3

• Flatpak: true

• Experimental: false

• Distribution: GNOME 43 (Flatpak runtime)

• Desktop Session: gnome

• Display Server: wayland

• GTK 4.8.3

• Libadwaita 1.2.4

• GStreamer 1.20.5

• Pipewire 0.3.66

Describe the bug
Currently, Kooha uses the old VA-API for hardware-accelerated encoding. However, those are deprecated and replaced by the new VA. Kooha should use that instead.

To Reproduce
Steps to reproduce the behavior:
N/A

Expected behavior
Kooha should use the new VA encoders for hardware-accelerated encoding

Screenshots
If applicable, add screenshots to help explain your problem.

Additional context
If applicable, please attach the logs from running Kooha in the
terminal with the following environment variables: RUST_BACKTRACE=1 RUST_LOG=kooha=debug GST_DEBUG=3 PIPEWIRE_DEBUG=3
(e.g., RUST_BACKTRACE=1 RUST_LOG=kooha=debug GST_DEBUG=3 PIPEWIRE_DEBUG=3 flatpak run io.github.seadve.Kooha).

[SeaDve]

I have already replaced vaapih264enc with vah264enc in main, however there does not seem to be replacement for vp8 and vp9