Integrated IPU6/MIPI camera not working on Dell Latitude 7440 under Debian 12

I have a Dell Latitude 7440 with an integrated FHD RGB + IR Camera, but there are no drivers. It's an IPU6/MIPI Intel camera.

sudo lshw -C multimedia
  *-multimedia:0 UNCLAIMED  
       description: Multimedia controller
       product: Intel Corporation
       vendor: Intel Corporation
       physical id: 5
       bus info: pci@0000:00:05.0
       version: 00
       width: 64 bits
       clock: 33MHz
       capabilities: pciexpress pm cap_list
       configuration: latency=0
       resources: iomemory:600-5ff memory:6052000000-6052ffffff

There is a ppa repo with the linux drivers (see a solution [here](https://askubuntu.com/questions/1473289/integrated-camera-not-working-on-dell-latitude-7440-and-7340-ubuntu-22-04)) . However this repo seems to work for Ubuntu, but not on (my) Debian (it cannot be added, when I try to add it I get AttributeError: 'NoneType' object has no attribute 'people'). Did anyone has an easy solution? I have found a quite convoluted solution [here](https://bbs.archlinux.org/viewtopic.php?id=287119) and I would like to avoid it. Any backport from Sid? I tried the backport firmware-intel-graphics (https://packages.debian.org/bookworm-backports/firmware-intel-graphics) but it did not do the job. Thanks, AB