[ Reason ]

Users using a recent version of mesa, eg. the version from
trixie-backports, have rusticl installed which uses version 2 of ICD
that leads to a SEGFAULT when using ocd-icl-libopencl1.

[ Impact ]

Users cannot use OpenCL when a recent version of mesa is installed on
trixie.

[ Tests ]

Test plan

0. Install dependencies and make sure rusticl is installed on
   the system (comes from mesa trixie-backports), which uses version 2
   ICD leading to a crash:

   $ sudo apt install \
       mesa-opencl-icd/trixie-backports \
       clinfo

   $ ls -1 /etc/OpenCL/vendors/rusticl.icd
   /etc/OpenCL/vendors/rusticl.icd

1. Run clinfo, which should crash before update and not crash after update:

   $ dpkg -s ocl-icd-libopencl1  | grep Version
   Version: 2.3.3-1
   $ clinfo
   ...
   Segmentation Fault

   $ sudo dpkg -i ocl-icd-libopencl1_2.3.4-0+deb13u1_amd64.deb
   $ dpkg -s ocl-icd-libopencl1  | grep Version
   Version: 2.3.4-0+deb13u1
   $ clinfo
   ...
   [no crash]

[ Risks ]

No regression risk identified.

[ Checklist ]
  [x] *all* changes are documented in the d/changelog
  [x] I reviewed all changes and I approve them
  [x] attach debdiff against the package in (old)stable
  [x] the issue is verified as fixed in unstable

[ Changes ]

This is an import of the new 2.3.4 upstream release as it contains and
only contains a fix for this very specific bug, visible in release notes
as well as in the debdiff:
https://github.com/OCL-dev/ocl-icd/releases/tag/v2.3.4

So better import this new upstream release as 2.3.4-0+deb13u1 instead of
cherry-picking the patch and using a confusing 2.3.3-1+deb13u1 release.

Thanks,

Agathe.