New debdiff in attach that enforces gcc-10 to build the dkms part on
s390x.

** Description changed:

  [Impact]
  
  Installing zfs-dkms seems to trigger a soft lockup issue as soon as
  zfs.ko is loaded. When the soft lockup happens the system isn't
  reachable anymore via ssh and on the console we can see some exlicit rcu
  stall warnings.
  
  This seems to happen only when zfs is compile with gcc >=
  11.2.0-10ubuntu1. Downgrading gcc to previous versions doesn't show the
  problem and zfs is working just fine.
  
  [Test case]
  
  On s390x install the latest 5.15 Jammy kernel and run:
  apt install zfs-dkms
  
  [Fix]
  
- Temporary workaround is to downgrade gcc.
+ Temporary workaround is to build zfs with gcc-10 on s390x.
+ 
+ [Regression potential]
+ 
+ Building a kernel module with a different compiler is never 100% safe,
+ we may experience potential crashes / panics if the ABI is not
+ compatible. Moreover, if we build zfs with gcc-10 we are going to lose
+ some of the performance benefits provided by gcc-11.
+ 
+ However these regressions are limited to zfs on s390x and without this
+ change zfs is broken anyway on this architecture.

** Patch added: "zfs-update-to-2.1.2-v2.debdiff"
   
https://bugs.launchpad.net/ubuntu/+source/gcc-11/+bug/1954676/+attachment/5553372/+files/zfs-update-to-2.1.2-v2.debdiff

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https://bugs.launchpad.net/bugs/1954676

Title:
  jammy 5.15 kernel soft lockup when zfs.ko is loaded on s390x w/ gcc >=
  11.2.0-10ubuntu1

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