Firefox v3d_drv_video.so on RPi4

After a recent upgrade Firefox on a RPi4 running Bookworm fails when trying to decode MPEG video. It reports

libva info: VA-API version 1.17.0 libva info: Trying to open /usr/lib/aarch64-linux-gnu/dri/v3d_drv_video.so libva info: va_openDriver() returns -1 

then falls back to software decoding which causes the system to hang.

/usr/lib/aarch64-linux-gnu/dri/v3d_drv_video.so does not exist, nor do any other *_drv_video.so libraries.

vainfo says:

rpi@system:/ $ vainfo error: can't connect to X server! libva info: VA-API version 1.17.0 libva info: Trying to open /usr/lib/aarch64-linux-gnu/dri/v3d_drv_video.so libva info: va_openDriver() returns -1 vaInitialize failed with error code -1 (unknown libva error),exit 

while DISPLAY=:0 vainfo looks for the vc4 library (which isn't there, either):

stfyc@wx-raceoffice:/ $ DISPLAY=:0 vainfo libva info: VA-API version 1.17.0 libva info: Trying to open /usr/lib/aarch64-linux-gnu/dri/vc4_drv_video.so libva info: va_openDriver() returns -1 vaInitialize failed with error code -1 (unknown libva error),exit 

Did some of these libraries get moved to another package recently? If so, what package do I need?